Neiji Rockheart (ネイジ・ロックハート) was the strongest individual on the Gladiator Island Ginunhive. Following Lye Batenkaitos' death, his status remains unknown.
Neiji is a large and muscular man with a big, sharp shaped tattoo covering the left side of his body. His hands are covered in cloth and he wears black pants. He has a ponytail and has some facial hair on his chin.
Due to his only actual presence being through Lye and Louis using Solar and Lunar Eclipse, there are no concrete examples of Neiji's personality.
Neiji was enslaved and sent to the Gladiator Island where he was forced to fight to his death. Due to his unique skill known as the Palm of the Fist King, Neiji was able to win every fight he took part in. After years of fighting, Neiji was granted was released from his slavery, as a reward for his victories. Sometime after regaining the status of a normal citizen, he fought and lost against Lye Batenkaitos who ate his name and memories, effectively erasing his presence from the world and claiming his ability for himself.
Great Power: Neiji is mentioned to be one of the strongest individuals on the Gladiator Island. There was no army around that was able to fight him. He's said to be the only warrior who survived hundreds of battles to the death with only his fists.
Palm of the Fist King: Neiji is able to strike his opponent with an extremely powerful internal attack. During the incident at Priestella, Ley employed this techinque against Ton, despite "Ryuuhou" being active which resulted into him puking and crumble to the ground. Roy Alphard also performed this against Julius to shatter his sword.