There quite a lot

Tesla going to a mental hospital and smashing his head and skull plus other scenes in Ragnarok Reversal such as graphic suicides and self mutilation

The there "My Eternal master " where there very graphic and violence scenes some involving self mutilation sekf harm and implied other deaths

Then there a fanfic rd where Qin slicing his heart to get Sasaki to love him and they drink each other blood in a blood brother sacrifice

Plus other stuff

There is a lot of deranged one including one where Beelzebub swallow tape worms

His death is graphic like maggots an he is crying while throat gargling and his friends watch him die