He has an extreme thirst to fight Homunculus, and is the record-keeper of 'Most Homunculus killed' (332 Homuculus) even more than the amount of homunculus killed by Hiwatari and Bravo combined. Ikusabe's powers comes from his Buso Renkin, the Jumonji spear Gekisen's recovery ability, and his special ability and habit to eat remains of Homunculus he's killed to increase his power and stamina, and the times he can use the recovery ability. Unlike Negoro, Ikusabe cares more about the process of battling then claiming victory, and quit the mission to kill Kazuki when he was defeated by Papillon. In the anime, it is not shown that he eats homunculus, nor does he send Papillon to Kazuki and Gōta. Instead, he falls to the ground after Papillon defeats him.

(Source: Wikipedia)