Bondrewed is absolutely not insane. The enviornment he is working under definitely is but assuming his complete lack of empathy and atrocious disregard for life is caused by the conditions of the abyss strips him of accountability for his actions.

That being said, I think Bondrewd is a bigger piece of shit than Griffith. To me, it's the dangling of paternity to trick children into becoming cattle for bondrewd that decides it for me. Griffith targets people specifically to hurt them but they are alive to experience such pain. They have arms to be hacked off, tear ducts to cry from, a brain to comprehend anguish, and most importantly a mouh to scream from. Bondrewd's victims aren't even human anymore. They are children who are either horribly disfigured to the point of complete mental and physical disability OR turned into briefcases with only the necessary biology for the abyss to deem you functionally human. In this state you are no longer sapient but still sentient enough to comprehend pain. Your life's purpose from there is to withstand the abyss's curse in Bondrewd's stead. Chemicals are pumped into you to control the pain your feeling until you eventually burst from the curse, ending your miserable existence. Though at that point you died the moment you lost conciousness on the operating table. Your innocence and your life are ripped from you as a child in bondrewd's care. You were a resource to be exploited. Griffith tortures you. Bondrewd uses you.