Sasuke Wavnd is the second Jninchuriki for the Ten-Tailed Beast, and thus he is able to transform into various transformations untill he complately releases the Ten-Tails'. When he taps into the Ten-Tails' chakra, it increases every physical aspect of his body. He is gifted with its enormous supply of chakra and stamina, immense strength, increased speed, accelerated healing (recovering from minor injuries within a few seconds to major injuries within half a day), and, at times, a nearly impenetrable chakra shield . So far, he has displayed a greater variety of forms than any other jinchūriki. Due to the unique seal placed on him, Sasuke has acess to all of it's chakra, but he can not controll all of it . Sasuke seems very wary of transforming into the beast or using it's chakra, preferring his Kekkei Gankai powers to the power of the Ten-tails. When he does use it's forms, Sasuke does not use his Kagegan.
This in truth is not a form of Sasuke, but is simply an enhancement that he acquires during the Invasion Saga. Sasuke acquired this by extreme rage when he belived Guru to be dead. This however did not release all of Sasuke's hidden power, since he was still only able to unleash his hidden power through fierce rage. Sasuke's abilities were enhanced along with the strength of his hidden power, and as a side effect continuously grew alongside his avantures with each battle, as stated by Armaldo. The first time that he receives this power-up roughly multiplies his power tenfold, allowing him to access a power in around the mid-10,000s range, though with the subsequent battles against Tigerstar and Roboracoon, he grows many times stronger. During one bout of rage, he was even able to subdue Hiruko's third form.
If Sasuke takes too mutch damage, he will lapse into a "berserker rage" while in close combat. In this state he lashes out with the intensity and aggression of an enraged animal and is even more resistant to psionic attack. Though he loathes it, he acknowledges that it has saved his life many times .
Kagegan Activated stateEdit
Not a true power release, triggering the Kagegan seems to activate Sasuke's body in many ways, making it stronger, more agile and giving him enhanced chakra , as noted by Armaldo. The "jump" in power Sasuke experienced the first time he activated this dojutsu was larger in relation than the later ones; this signifying that the power released by the first Kagegan activation stays at least partially available even after the dojutsu is deactived. With this, his physical power and chakra increase considerably making it possible for him to free himself from any control such as the shadow possesion technique  . In this form, he displays waves of chakra towards many enemies and is capable of overwhelming them without any problems.
Just by simply taping into the Ten-Tails' chakra that naturaly mixes with his own, Sasuke's body becomes enchanced, and enters the intial transformation ; capable of realizing its power and turning the tide of battle in his favor. In contrast to Azuko, Sasuke's pupils first become white, then become stilted, and then turn red while displaying this power . He then gains fox-like ears, and three thick wisker markings on each cheak, and next his nails, canine teeth, and red-turned hair will grow longer and sharper, as it stands on end, making him more into the appearance of the Ten-Tails. While he can still stand on his own two feet, Sasuke can move at greater speeds by maneuvering on all fours in a manner similar to the Four Legs Technique used by the Inuzuka clan . Depending on how much of the Ten-Tails' chakra is unleashed, the black/blood red chakra is capable of glowing around his body in an untamed way.
Even though this is the weakest state of his jinchūriki forms, it still increases Sasuke's physical strength and durability, to the point of being able to stop a massive rocket going at incredible speeds , and healing rates well above most shinobi, even able to regenerate a heart pierced by a Gerterider's Shomontize instantly . This form also increases his speed to such levels that nothing short of a fully matured Kagegan is able to track his movements ; leading this form's power to be compared to Sage Mode.  He can also use his boosted chakra as a shockwave, sometimes merely using a roar or thrusting his fist out to send a rush of energy at his opponent . Besides aumenting his physical abilities, this form also boost his sences , and ninjustu giving him access to his stronger jutsu such as his Quizen variants and his more powerful eleamental release techniques . Sasuke has also shown to have incresed chakra controll (can climb walls and walk on water without the use of Chakra) and can even sence chakra around him, to the point where it can be an extra sence that allows him to sence incoming attacks . The acid saliava that Sasuke can prouduce becomes unlimited, to the point where the acid saliava compleately replaces his normal saliava.
Until special training fro Xion, Sasuke could only reach this state through sheer rage or if his life was in imminent danger. However, after having an inner talk with the beast, and acepting it's deal, Sasuke is able to tap into this form at will, or by simply telling the Jyuubi to give him some power. 
Chakra Cloak Released StateEdit
This is the first "true" power release state of Sasuke . This form appeared when Sasuke was eaten by a summoned snake in Heundo Mundo, and his comrades being attacked. In this state, the manifesed chakra from his intial form becomes permently stable outside his body. It is surrounded by a flowing aura of distinctive Bijuu chakra, thick enough to be seen with the naked eye . Entering this state makes Sasuke a lot more powerful, incresing all of his previous powers to the point where he was able to kill an entire team of higher ranking missing-nin in a short time. His techniques also get a powerup, as he has demonstrated both Golden Rasengan  and an incomplete version of Takaken  in this form. The chakra seems to react to Sasuke's will, him being able to release a more powerfull wave of it with a roar and mold a Rasengan with one hand only (he usually needs the assistance of a Clone ).
Compressed Release StateEdit
In this form, the chakra in the previous transformation becomes compressed , thus making it appear even thicker from the sight of the naked eye. Due to the now compressed nature of the chakra, Sasuke can reach further in power than in his previous cloak state, increasing both his strength and speed even further. Futhermore, the fact that all of his energy is "compressed" when using this form means that usage of this power doesn't expel as much chakra as other jinchūriki froms do from the point of activation; thus allowing Sasuke to use the chakra cloaks at a much longer duration than any other jinchūriki of his level. With enough usage and acquired height, Sasuke can even appear as though he is flying.  While in this state, his speed also increases greatly; great enough to dodge Amaterasu several times with little to no effort. His strength and chakra tenacity has increased immensely from his base state; to the point where he could grab and crush AlphaRay's Quizen with his bare hand, without even coating it with chakra. By employing the compressed aura of the Ten-Tails, Sasuke can use its chakra to extend the range, reach, and force of his physical attacks. Punches thrown that appear to miss, actually end up sending the opponent flying backwards due to the sheer force of the chakra. Whether a punch connects or not makes no difference, as one punch can completely cripple or even finish off an opponent, makeing Sasuke near-invincible in terms of hand-to-hand combat.
However, this power does not come without a serious drawback. Becuase the chakra is compressed into an incredibly thick form inside his body, it begins to damage it, causing cells to die and regenerate in an accelerated rate, leading to his lifespan shortening. However, this shortening of his lifespan is not as great as that resulted by most Jinchūriki over-using their power due to this form being controlled.
Version 1 TransformationsEdit
Using his own chakra, Sasuke can force the seal to free some of the Ten-Tails' chakra for his own use. When done this way it's chakra freely and quickly forms a demon cloak that surrounds his body. Once activated, his canine teeth and nails grow long and sharp. The cloak itself is black with a blood red outline, and gives Sasuke paws of chakra around his hands, hoves on his feet, and horns on his head. He can also create an additional set of horns on his forearms to use for his Lariat attack. While the chakra is still compressed, thier appearence is similar to Naruto's first three tailed forms; transparent with bubbles of chakra forming on the surface. Other than an incremental increase in his strength, speed, and chakra, there are no obvious differences between the number of tails.
All the physical traits of the previous forms were present and slightly altered, including black rings that surround more berserk-looking eyes, and longer claws, teeth and ears. In this form, Sasuke fights with his elongated, sharpened claws instead of his fists, and runs at greater speeds on all fours, making him more like his beast. This form also comes with an additional bonus: the extra chakra formed a cloak that becomes a complete shield around his body, in the shape of a coyote, complete with long ears, long horns, a lions mane, and an octopus tentcle as a tail, referred to as the "demon beast shroud" (妖狐の衣, joiu no koromo). The full powers of this state are still unknown, but with it and sheer willpower Sasuke could keep moving, even in his heavily injured state. He commented that he is moving his body with his chakra like a puppeteer, further indicating the seriousness of his injuries. 
Sasuke's most powerful weapon in this state is the chakra itself, and it appears to have a mind of its own; when a strike that was meant for Darcia missed, the chakra itself stretched off of Sasuke's arm and managed to hit Darcia before he had time to react. Since the chakra is sentient, it is extremely difficult, if not impossible, to predict, as Sasuke can be easily followed with the Sharingan, but the chakra can not. The chakra can also stretch far from the body, as when Sasuke is shown using his 'arms' to attack from great distances. It seems Sasuke can freely control the chakra cloak and use it's tail and claws as a mean of attack, resulting the unique Black Beast Fighting Style. Sasuke is also seen as being able to use the demon fox cloak's chakra tail like an extra limb, while hanging upside down. The chakra around his body grants him some measure of protection, enough that ordinary attacks like Fire Release: Great Fireball Technique will have no effect. The aura in this form is calm, but it is still powerfull enough to inflict a painful burn to anyone that comes into contact with it for too long. However, the demon cloak is not without its drawbacks; after Sasuke uses his left arm for a number of attacks, it is left numb from overuse and the constant damage of the Ten-Tails' chakra on his body.
Two-Tailed Form Edit
His physical characteristics matches the first two forms, but his red eyes, wisker markings, and canines grew larger, and his lips acquired a black outline, similar to his tailed beast. The chakra shield's only difference between the one-tailed and the two-tailed form was the extra chakra tail that formed. The red hair brought on by the original transformation becomes longer and rigid; any hair that hung loose in the one-tailed transformation is now raised. Increased energy radiation causes the aura to take on a jagged, fierce flame-like appearance rather than smooth or flowing. Because the energy output and radiation is higher than that of the first transformation, the aura pulses at a higher frequency, like the type 2 aura. Strength and energy output is multiplied manyfold; such that greater amounts of increased energy can be used at once for much more powerful energy attacks, and even speed is augmented incredibly by the boost. Sasuke's personality changes. He becomes a hotheaded, merciless fighter after transforming, opting to torture Gatr rather than kill him, despite Starsuke's pleas.
One of Sasuke's new abilities that this form granted was being able to fire the chakra fro it's cloak similar to the Ten-Tails' own accounted justu. While in this state, Sasuke is somewhat in control of his body. In the anime, he punched a tree, destroying it and a long line of trees behind it.The amount of chakra produced by the two-tailed transformation was so powerful that Sasuke's clones were dying and even shinobi from far away could not only feel it, but be frightened by it.
The three-tailed form looks similar to the two-tailed form, but with the Ten-Tails' features becoming even more pronounced. The trademark characteristic of the transformation is the hair: the rigid hair of the previous state becomes even more Rigid and spiky, and grows down to or sometime passes the user's waist. Energy radiation is so great that the aura pulses at an extremely high frequency, almost to the point where it seems static; the sound of the aura is also pitched even higher than that of second transformation. Bio-electricity, like in the Two-Tailed form, is again constant, and may reach further outward from the body than before. Another notable change is that Sasuke seems to "glow" while in this state, more so than before, where the skin and clothes color were lightened, but not as much as the color change of this form (this mostly applies to training gi). His eyes later glow , similar to the four-tailed transformation, but they can return to normal. 
In this form, the chakra it produced was caustic, such that the air around Sasuke began to damage things around him. The first time that this form was used on Earth, its power caused tidal waves and hurricanes and nearly shook the planet apart.  (His subsequent transformations to the form were controlled enough to prevent such dramatic side-effects.) In addition, this power could be sensed even as far as the distance between Earth and Supreme Kai's planet. The difference between Three Tailed Transformation and Second Tailed One, its predecessor, are immediately noticeable as speed, strength and endurance are all pushed past normal limits; and with the demon beast shroud's increased protection and attack power, Sasuke's roar has the power to create a powerful sphere of destruction, capable of destroying the Tenchi Bridge. During the fight With Tigerstar, Sasuke was able to use the chakra shield's tails to mimic arms and wings for semi-flight.This form is so powerfull, that Regular surpression seals will not work on it and to bring Sasuke back to normal, he must be hit with an implanted arrow. 
When entering this form, Sasuke's pupils and his irises will vanish completely, leaving the appearance of empty eyes, which glow like a blood red full moon, mostly in turn to the power and bleak rage. In this form, Sasuke's hair color differs, his body is covered in golden fur (as opposed to Sasuke first haveing red hair). Sasuke when calling even futher power gained a shadow trim around his empty eyes. The hair is lengthened, to the point where it goesdown past his shin. The aura in this form becomes even more powerfull but instead of the chakra 'boiling', it blazes much like a fire. The massive power and speed enhancements brought on by this form easily make it the one of the strongest Jninchuriki forms in the series. For example, while in his three tailed form, Sasuke was unable to even phase Maxumus, as soon as he transformed into his four tailed transformation, their roles in power became polar opposites, with Maxumus being almost unable to hurt Sasuke at all.
In this transformation, Sasuke's wisker markings glow bright white and his eyes glow devilish red. This form increses his power drasticly, and his mouth becomes similar to a wolf's or a dragons equiped with sharp teeth (he still keeps the lip outline gained in the two-tailed transformation), which allows Sasuke acess to the Menceing Ball technique.
The chakra around his body becomes more extreme, to the point where it is extremely diffcult for him to stand on his two legs, even though he can move mutch faster and fight better on all fours. In this form, Sasuke can create earthquakes and all of AlphaRay's physical and mental eleaments are stronger.
During the Eternal Spring Isle arc, Sasuke seemingly dies at Rayquaza's Dragon Pulse after a long battle where Sasuke used up all his chakra and Kekkai Genkai powers and still did not even managed to land a scratch on Rayquaza. After hearing Sussette's desperate cries, the Ten-Tails' takes over his body long enough to enter Sasuke in a version 1 form form but unlike his previously seen form. The chakra cloak acording to Wolfbane is mutch darker and siniaster than the previous form. Sasuke's appearence changes very little, but now with spikeyer hair and even longer fangs and canines and ears, Sasuke has horns on his head and a well difined muscular structure. This form was able to protect Sasuke from Rayquaza's Outrage, and even reflect Rayquaza's Dragon Pulse back at him. This form, also noted by Wolfbane has so mutch chakra srounding Sasuke that he is surprised Sasuke can move, let alone be alive. Some abilities that this form grants are a more powerfull cero, Lariat speed and strength.
Version 2 TransformationsEdit
By tapping into the Ten-Tails' chakra reserves and forceing the seal open, Sasuke can enter "version 2" transformations. As stated by Sabu when he witnessed the previous host's transformation, this is done by forming the chakra into a human shape. These transformations are meant to give him an edge in battle without completely releasing the Jyuubi, as that would endanger anyone around him. When first activateing these transformations, it's chakra began to burn its way through Sasuke's entire body, completely destroying his skin while rapidly healing it at the same time. Sasuke's body was eventually covered in a mix between the Ten-Tails' chakra and his own blood. Everything from his face to his chakra tails became completely solid and his eyes lose its characteristics and become empty glowing circles, surrounded by a black mask of chakra. While in this form, Sasuke becomes more muscular, and if necessary can create chakra bones, such as the Ten-Tails' skull, to increase the strength of his attacks.
In the end, despite it being one of Sasuke's strongest forms revealed so far, this transformation is his greatest downfall. Because the demon aura is constantly destroying and creating new cells, it also shortens Sasuke's life, similar to Tsunade's Creation Rebirth. Also, because the Ten-Tails' has complete control, Sasuke will attack anything that moves, including his friends. This discourages Sasuke from using this state more than the fact that it shortens his life.
The three-tailed version two transfomation had the power to create destructive shockwaves as well as turning into a comet as it demonstrated in the outer space battle agist the meteriex. This form had enough durability to resist moast justu, even ones of B-Rank.
Sasuke goes into a three-tailed state during his battle with Grimmy. In this state, his sonic roar is powerful enough to push away a powerful B-Rank technique from Kai, who was a former Kage. The chakra this form brings out is rough and intense, as Sasuke commands his friends to retreat to the treeline before he was forced to transform.
In this form, the Ten-Tails' has complete control over Sasuke's body, making him a mere endoskeleton for it's chakra. The chakra's internal support became Sasuke's physical mass, with every living thing in its way a target. The four-tailed form had all the benefits of the other tails, with upgrades. With a simple wave of his hand, it could create a shockwave of destruction. The demon shroud, while being solid, was so hot that it could burn skin on contact and its defensive power was so great that not even the legendary Sword of Kusanagi could pierce it, only bending it slightly. If Sasuke was hit, the chakra itself could form another body and strike back almost instantly. Finally, Sasuke had the ability to charge a concentrated sphere of chakra, consume it, and then fire it in the form of a massive blast of chakra with such force that it could destroy three Rashōmon gates. In the anime, it could generate numerous bodies, almost completely altering its own form into an amorphous blob, with which it was able to attack Pein from all directions. Also in the anime, just one slash from its claw made a tornado to attack Pein's Deva Path.
In the end, the four-tailed form was Sasuke's greatest downfall; as the life-shortening disavantages grow exeptionly after reaching this transformation. Also, unlike the other two forms Sasuke has absolutely no control over himself.
In this form, incresed powers cuppled with earthquakes and it's sonic roar, Sasuke seems pretty invicible. Though as stated by himself, this form is lesser used, due to the chakra and stanima drainage. Though this form's power limit is yet to be revealed, it managed Peins strongest Sinra Tensei and sent the attack right back at him with Sasuke's own shockwave. This form was also able to withstand a Huge atomic bomb explosion and no clear physical damage was seen.
Nine-Tailed Form Edit
In this form, the Ten-Tails' bones can begin to form out of the intense chakra around his body, attached to the body with several thick chakra ligaments. With its raw power, Sasuke was able to break out of a Chibaku Tensei with brute force. Similar to the version 3 forms, this form is able to unleash a concentrated ball of chakra without first ingesting it. Without even being fully charged, the attack had enough energy to create an enormous crater and almost destroy Earth.
Version 3 TransformationsEdit
In this form, the Five-Tails' bones form out of the intense chakra around his body, attached to the body with several thick chakra ligaments. Greatly increseing Sasuke's durabilitly, and risentence from surpression seals or other methods.
Version 4 TransformationsEdit
The Version four jinchuriki transformation, is where the muscle tissue beginns to grow on the bones from the previous transformations. The only things missing in the Version four-tailed transformation from the Ten-Tails are the skin, and fur. This form just like many others brings Sasuke closer to the Ten-Tails, and disorts the seal even more than the previous transformations. Also, unlike the other transformations, Sasuke is only capable of using this form at, or beyond eight tails.
This form is just exactly like the Ten-Tails, and Sasuke has acess to all of it's abilities. This form is the biggest so far, being about the size of the Ten-Tails' itself. Sasuke has no controll over this form. Darcia has noted that this form causes an extensive amount of internal damage and chakra loss. Even during this transformations brief appearence with the battle agist Xanzo, Sasuke needed immediete healing plus two days to recover. The only diffrence between this form and the full form is the obvious diffrence in Size.