Don't Jump in the Middle of a Dogfight
As I saw it (YMMV), cthulhu erred as is his wont by attempting to intervene as a peacemaker, unwittingly placing a target on himself.
As Will Rogers or Proverbs or something said, don't argue with a fool, lest you be mistaken for one.
Or as m' daddy tried to teach me, don't jump in the middle of a dogfight. I had to re-learn that one a few times.