A short man despite his age. He has black wavy hair and carries a katana on his back. He wears a mask covering the lower region's of his face and the standard Jonin outfit. Born only a few three months after the Ten Tailed Fox attacks Amegakure, Sanji grew up in Kirigakure because his parents fled Amegakure after the fight with the Ten-Tails. He joined the Seven Swordsman of the Mist at age 14 and shortly after left the village in search of his brother Tora Uchiha and his cousin Ryun Uchiha. At some point during his 13th year of life, theThree-Tailed Giant Turtle was sealed inside of him.
Sanji, like Naruto Uzumaki, is a Jinchūriki of the Three-Tailed Sanbi. Unlike the Nine-Tailed Demon Fox, Sanbi doesn't have an unnaturally large supply of chakra that Sanji can use. Instead, Sanbi's presence inside Sanji allows him to manipulate water at will. As a added bonus for Sanji, Sanbi itself can move the water on its own to protect Sanji from any harm it can in order to preserve its own life. It should be noted however, unlike Naruto's constant battle for control over his body with the demon fox, Sanji is technically never subjugated to this. This is because Sanji is in harmony with his bijuu.
The first stage of his Jinchūriki transformations. He gets long incisors, his eyes turn bright green and begin to look similar to the Rin'negan. His nails also get long. His face also gains a scar-like mark down his right cheek. Also a green chakra begins to glow around him. In this form his strength and speed increase dramatically. He also never uses his Sharingan in his Jinchūriki forms.
One Tailed Form
When his anger or sadness (or both) exceeds a certain level, his hair stands straight up and a green Demon Turtle's Cloak forms around him. In this form he is even faster and stronger, he also moves on all fours. The Cloak protects him like the Nine Tailed Fox's does Naruto.
Two Tailed Form
Out of all his Tailed Forms, he does not stay in this form long. His anger and emotions are beginning to take over. His punches are now strong enough to make a small crater in the ground.
Technically this isn't a Jinchūriki form as its a transformation into Sanbi itself. The Three-Tails is depicted as having no hind-legs, with only a pair of fore-legs and its three distinctive tails. Its right eye was constantly closed, indicating some sort of injury. Because of this, it was particularly vulnerable to attacks directed at its left eye.
Other than being a very fast swimmer despite its size, the Three-Tails' could roar to repel attacks; it could produce a large tidal wave that spread away from it in all directions; it could strike with any of its three spiked tails to break through most defenses. Its skin was resistant to attack in a similar fashion.
Of the beast's more specialized abilities, it could produce a hallucinogenic mist that exploited the victim's insecurities and forced the victim to face them. It could also shoot white, Menacing Ball-like shockwaves. When it swallowed something, thousands of "mini-clones" of itself would attack what it had eaten within its gut, presumably to facilitate digestion.
Sanji is masterful at swordsmanship, capable of utilizing his size to effectively counter and outmaneuver his opponent. His skill in swordsmanship is evident in the fact that he is one of the youngest Jinchuriki and one of the youngest to become a Seven Swordsman of the Mist. His skills in swordsmanship are great enough that he rarely uses even his ninjutsu or Sharingan in battle, of which he has shown great proficiency with.
Sanji's chakra has the same effect as his Tailed Beast as it is an elemental representative of Water and Ice. His chakra is said to be very large and "cold". Even before he became a jinchuriki, his power was immense and uncontrollable. This cold chakra of his reflects his attitude as well.