not at all besides maybe the king. Like this is supposed to be your close family, having them all be a bunch of cackling villains would kind of defeat the point of actually making you choose.
Thankfully it doesn't look like they're actually going to be evil. Imouto is cute and bubbly, Marx seems to have some sort of moral code, Camillia does show worry for the Avatar, all of them seem worried for the Avatar when the confrontation between the two families happens. Other than them wearing all black they don't really seem to show any "evil" traits at all, besides the king who looks outright demonic and is implied to have killed the Avatar's father and taken him in against his will, and also to have done something to make Marx doubt him (possibly the same thing). Even then I'd hope he has some depth and isn't just Generic McBadGuy who does Evil Things because he's Evil.