🏹 - would your muse ever kill and why
She definitely would kill, even if things were different and Sirius had raised Eris she still would kill if it was entirely necessary.
Having lived with Walburga, she was taught many things in her short time there about the Dark Arts and the Unforgivable Curses. She knew the spells, the proper wand movements, everything. And having been exposed to Bellatrix they were spells the girl had learned to use loosely if needed. So she was taught young that it was okay to injure, maim or kill.
It wasn’t really until Hogwarts that Eris had learned murder was a last line of defense, not the first (not that herself as a person would actually jump to murder, or curses in the first place. Ya girl is more of a wandless, ‘punch you in the face’ type of person).
She used the Unforgivable Curses a lot in the second war