ToME: the Tales of Maj'Eyal

I want to play a cultist of entropy run but I don't want to use a mod to unlock it. I have another character with the book, but I can't seem to follow basic instructions. Can someone explain it to me like I'm 5. I am using the healing infusion, then I shoot the dummy? Iunnno.... helpppp

If you want to generate backlash with a healing infusion, then you need to damage yourself. See Tome4 Wiki: The Day It Came.