Welp I was able to beat the game, first run as archer after all my other builds died to spikes on final boss.
I got the bomb relic and at first used phantasmal shivs and spikes + blocking which was painfully slow, but then found the phantasmal arrow wand that carried me thru the rest of the game. For most of the game after I got the build together I was ending every fight before enemy first turn, but it seems like it gets outscaled pretty fast in free play.
Really fun game.