Roto was one of the earliest enemies during the Dark Tournament.
For a demon he was pretty weak.
Kurama almost killed him immediately.
Turns out he had a button that signaled to his demon brother to kill Kurama’s mother. Such a dirty trick.
Basically forcing Kurama to surrender or else.
Luckily, Kurama was a master genius. He planted him with a nefarious seed that immobilized him. Allowing him to get the button instead.
After begging for mercy, Kurama says he doesn’t believe in mercy. And the evil demon is killed when Kurama releases his demon energy into the seed. I love that moment.