I was able to beat him 3 or 4 days ago, after the rock pile thing wasn’t part of the fight anymore.

Overwhelming force: strength build, vulnerability , and the card that gives you strength when you lose health on your turn, combined with multiple cards that triggered damage, and a power that dealt 1 hp damage at the beginning of my turn.

Accept that you will lose a few cards and build redundancies.

I’ll look up my build later.