Jibaku-kun

ジバクくん

Jibaku-kun serves as the primary Spirit of the series. In contrast to the other eleven Spirits, Jibaku lacks any distinguishing traits; he is simply bald and wears no adornments. Jibaku also possesses no special powers, and, like all Spirits, he triggers a massive explosion when he opens his hands.
Jibaku is the Spirit of Primas, the Great Child of the 1st world. Prior to becoming Baku's Spirit, Jibaku belonged to En, who was seeking a successor to enable him to become a Great Soldier in World Zero. Although Jibaku is in constant conflict with Baku, they hold great respect for one another, and he always becomes embarrassed when praised or acknowledged by Baku.