I went to the House of Hope, stole the hammer and killed Raphael. Good riddance. Doing that tipped me over to level 12, which I think is the cap for this game. When the fight started I thought I’d just make an attempt at it to better plan a proper go at it, but I won first time.
I started by rolling a 20 first go to get the big demon dude to side with me, the main benefit of which was not having to deal with him during the fight - he killed Hope’s sister who I would otherwise have probably tried to spare and did a little bit of damage to the other enemies but nothing significant. Then I threw up a globe of invulnerability using my first character to get a turn, which was Karlach. Probably should have realised that using frenzy would make her lose concentration but I didn’t, so that was a waste of a scroll and a turn. Had the next character use another scroll to make my party and several enemies invulnerable and started using ranged attacks on enemies outside the globe or melee when they were close enough to hit without my guys stepping outside. Also had some luck having Karlach and Lae’zel pick up enemies inside the globe and throw them at enemies outside the globe. Plus Hope has a spell that just eliminates one enemy, even if they’re in the sphere, so I got rid of a couple of them that way.
With the minor enemies out of the picture I gave up on the sphere once it ran out and had my team split up to take out the soul pillars. Gale was able to disable Raphael with hold monster, which lasts 10 turns. Fight won, right there! Except it turns out he has a thing that makes status effects wear off after one turn, so I started moving my party who had scattered to the pillars towards the corner where he was before I would run out of spell charges/scrolls. I got him down to about a third of his health before running out, then he transformed and started throwing spells around, immediately getting most of my party close to death and inflicted with hellfire. Hope’s group heal got them back to decent health and I remembered Gale has an ability from somewhere that lets him use a spell without a charge so I was able to hold Raphael again and finish him off with Karlach.
Annoyingly two of my characters were killed by hellfire while I couldn’t do anything during the cutscene after the fight.