Pronounced Ya-mi Aku-hey. Yami Akuhei is a mixture of roots though primarily Japanese. Yami means "Dark" in Japanese, while Aku is the root of "Akuma", essentially meaning devil or satanic also in Japanese. Hei, is the ending of "Serpent" or "Hydra". Together this makes his name's meaning something of "Dark Devil Hydra/Serpent".
His last name is inspired by one of the most powerful of the Sequence Destroyers in the Third War of Armagus: Akuhei Yamorochi, a revered being whose exploits were responsible for the victory of the NOS. According to Lukain, Akuhei isn't that far off from his predecessor.
悪弊 is the Kanji for Akuhei.
The pattern on Akuhei's coat is inspired by the Leviathan Cross, the alchemical symbol of sulfur.
This pattern is shared with Serza, who has it on the hilt of his weapon, Ophius.