|Location||Pitch Black World|
|Affiliation||Pitch Black World|
Gokuen (獄炎) is a character that has yet to formally appear in any series. He is Heller's father.
He has raceless white skin, like most characters, and eyes with red sclera with black pupils, on which he wears square glasses with black rims. His long white hair is tied into a ponytail by a black ribbon, and has a wispy quality to it, flowing almost like smoke. He wears a black kimono with grey obi and has a kiseru.
Heller is Gokuen's daughter.
Satanick had a battle with Gokuen in the past, and apparently lost to him. They might be on fairly bad terms despite sharing an affinity.
- "Gokuen" means "Hell" or "Prison Flame"
- It is shown in one of Deep-Sea Prisoner's artworks that Gokuen viciously defeated Satanick in a battle they had in the past.