Mastema

Devil Mastema (マステマ, Masutema) is a fictional character in the manga series of Shaman King.

About
Devil Mastema is a demonic spirit that Lyserg Diethel fought during his training in hell with Pascal Avaf 's guidance.

Shaman Fights Second Round
When Lyserg was in his own personal hell, he was attacked by Devil Mastema.

Anime/Manga Difference
Devil Mastema is a manga only character and never appears in the anime.

Trivia

 * Lyserg's strongest oversoul - O.S. Mastema Dolkeem, is named after it.