Manic is far from toxic. In fact, he's probably the most well adjusted in the friend group aside from Sonia. He's quick to defend his sibs when Aleena or Uncle Chuck (or Knuckles)
go crazy, tries setting up a date for Sonic and Bartleby despite being mistreated by the latter, is the only one aside from Bartleby that tries looking for Sonic in the Secret Santa episode, calls Knuckles out for peeking on Athair while he's pooping, calls out the photographer for being a pedo and comforts Flora in the bakery episode. He's also the only one in Battle With The Boys to show remorse for his rival.
Uncle Chuck also seems to be getting better. The last time I remember him beating Aleena was in the 2018 Thanksgiving Special, and while he still tries to fuck her sometimes, it's less forceful, like when he sends her flowers or texts her "let me touch your ass"