Third Sin, Greed.

Greed-based demons tend to obsess themselves with something, making that ‘something’ more important that their own lifes. This doesn’t mean they’re more humble or better than other Sins, since their obsession can be something dangerous. Some might want bones, some might want to protect their leader, or some of them might just want to kill more.

While Geiser tries to fight against his own Sin, it ends up being pretty impossible to ignore it completely, though he focuses it on something that can be helpful, which is his friends, his family. Protecting them, he feels like he can forget about the fact that he’s a demon, that he can forget about his Sin. Though, Greed is still a Sin, and a Sin is never good, no matter the intention. It’s just a question of time for him to find out he can’t protect everything all the time… Especially from himself.