Animal: Chameleon (Leon)
Special technique: Chaos Shot
what we already know:
– He calls himself the best hitman in the history of the Mafia, and no one dares disagree
– Currently acts as tutor to Sawada Tsunayoshi, 10th generation boss of Vongola
– Tutored Yamamoto Takeshi for a while in Future arc
– Formerly tutored Dino, current boss of Cavallone
– Formerly partnered with Bianchi as an assassin team
– Declared dead in the Future arc (the present-day version was brought into the future, the same way as the present-day Vongola guardians)
– He is strongest of all the seven, bar none, according to Lal.
– He called himself “Reborn” only AFTER they were converted into the Arcobaleno. (Nobody has given his real name, though, not even him.)
– Returning from self-exile after the conversion process, he went to Shamal to have his past erased (I don’t think this means he erased his memories, because his memory for the conversion events seems to be fine. It probably means he had his previous records and all traces of his previous existence as a hitman erased and removed).