BLEACH THE MOVIE: HELL VERSE

Bleach: Jigoku-hen is set in Hell and features a fully Hollowfied Ichigo. The movie centers around Ichigo and his friends heading into Hell with the assistance of man named Kokuto to stop the merging of the two realms. However, Kokuto gives Ichigo a warning - he mustn't Hollowfy in Hell, or he will lose control of his body and never be able to return... — Description from AniList community (anilist.co).