When using KillAura on 1.17 there is a small chance of KillAura hurting you.
Can you reproduce this? This shouldn't be possible. Are you sure you are not hitting something with thorns?
@dyiing I got hurt when I was attacking a creeper in a cave and I was wearing iron armor no enchants. Its a low chance though. The creeper attacked me from a distance like it hit me instead of exploding. I can try and get a clip.