Ok, so after reading multiple views on Galeazzo Maria Sforza from different sources (books, letters, archives, recollections/communication between him & other ppl), I really believe his reputation of being Literally Satan™ is greatly exaggerated and most likely untrue.
There's a ton of circumstantial evidence and contemporary bias at the time to suggest that a lot of the discontent towards him was by nobles & old heads (very common in cases involving supposed "tyrants"), and their beef with him was because he either spoke/acted with them in a manner that was no different from commoners, or that he decided to effectively replace his court with more technically skilled people i.e. he wanted a meritocracy.
Then of course, there were his brothers who tried repeatedly throughout Galeazzo's reign to overthrow him, the most notable of all, Ludovico (who did end up becoming the new duke, after poisoning Galeazzo's son no less). They (sans Filippo Maria) are heavily implied to be involved in assassination attempts when you read reports of the incidents and check everything that happened after said attempts. And don't get me started on the guy who incited his 3 assassins, Cola Montano. This guy used to be Galeazzo's teacher and would apparently punish him by beating/flogging whenever he misbehaved, and already held a grudge against Galeazzo before he even came into contact with those assassins.
Seriously, it's a lot. But yeah, after going through it all, I'm inclined to believe that this is another Borgia situation. I'm not saying Galeazzo was the nicest guy ever, but in terms of being a duke and how he treated others, he was just alright. Even his critics have said the stories about sexual assault/torture have no evidence to back them up. I'd compare his reputation to Cesare Borgia's but maybe his daughter Caterina wouldn't appreciate that lol.
