I'll answer from all 4 of my characters povs lol, since they're all different

Slytherin: well it's not exactly a good thing to use, imperio arguably has no long term harm but the other two arhard to jusyify. But even so, if it's what I have to do to protect the ones I care about then I'll do it, no questions asked, the ends justify the means.

Gryffindor: imperio doesn't hurt anyone, it actually saves people since I won't have to fight and potentially hurt them. I'd never touch Crucio, and Avada Kedavra is an absolute last resort.

Hufflepuff: there is never a justification for using any of them. It's not your right to choose who lives and dies, control people like puppets, or torture people.

Ravenclaw: oh I don't know but they're fun! My favorite party trick is the ole' surprise Crucio. Good times...