Riz/History

History
The whole fact that he accidentally killed Tem is made tragic by the certainty that all bears are now forced to take medications that limit their strength when they grow beyond 200 centimeters in height. These come with terrible side effects. Tem's friendship made Riz think he could manage without his pills. Riz remembers that Tem accepted him exactly as he was and remembers them hugging each other, before his memory screws up, after having Tem annihilated.

Although, from the first scene of the manga, we know that Tem died cursing his own killer. Later, Riz admits that he was so happy that Tem saw through his exterior facade the "monster" that was inside, that he felt so much affection for Tem for revealing his true sinistrous personality that he altered his memories to make them happier, but it seems that the event has gave him a taste for carnage. It has only advanced in recent chapters, to the point that he now sincerely believes that Tem wanted to be devoured and Riz eating him alive will make him his "best friend".

He has an extremely incredible strength, even when compared to other carnivores and has to regularly take force-limiting medications to make sure he keeps his strength under control. He stopped taking them in preparation for his big brawl with Legoshi.