Idk if you still need help, but for the "You're the monster" achievement, you first have to get the star shield upgrade, then ask a friendly Kaishi or Tsughos to eat you while it is charged. They will try, the star shield will go off, and boom.
I got that one on accident XD The only achievements I need to beat now are the Wand of Amethyst and the milestones. Got all of the secret achievements
