I don’t agree that how Percy has been writing Beast wasn’t building off of previous stories, I also wouldn’t categorize it as character assassination. Beast has been on a dark path since Decimation, Percy’s iteration of the character is the culmination of over a decade of previous stories showing him making increasingly unethical choices. Also there seems to be a lot of fans who think his portrayal in the 90s cartoon is comic accurate and it really isn’t. Hank has always been a bit of a jerk who thinks he knows best since as far back as the 60s.
What I object to about the Percy Beast story is, and this could turn out to not be the case the story hasn’t ended yet, how it seems like they are setting up a blank slate clone to take his place. It feels lazy to essentially redeem the character without having to do any of the hard work of writing an actual redemption story. A get of jail free card.