Harry is very unlikely to kill. He wouldn’t even try to use that killing curse even if his life depends on it. Nope.

Anya might kill but in self defense, she did end Rasputin’s life by stomping on his magic reliquary after all.

Lena is so not a murdery type. She can’t fight with a sword to save her life at all. She is the least battle ready of my lot.

Isabela, oh God, Isabela. She is so capable of killing if she could. Full of unhinged energy. She is so unhinged and if she has beef with something or somebody, she will lose it.