Sai

Sai, known as Phantom Thief X (怪盗X Kaitou Sai) is his name formed from the words Monster Robber X.I. (怪物強盗 X.I. Kaibutsu Goutou X.I.). This is abbreviated into the name 'Kaitou Sai', and thus X is pronounced Sai throughout both the Anime and Manga. Sai is a mysterious human with extreme strength, speed and the ability to alter his own cellular structure; because of this, he is able to change his whole body into any human form available, and also grants him indestructibility. He is seen to survive multiple injuries…