Who is more evil? I, personally, think Zira is more evil. I can't recall any point at which Scar showed any point at which he could consider any alternatives to killing. Zira, in My Lullaby, said something to the extent of 'my foes, I could forgive. Trouble is, I know it's petty, but I hate to let them live'. Zira acknowledges she has it in her to forgive, but much rather take the route of violence. That is why she is more evil than Scar in my opinion.