What build for 40/40?

I’m currently farming Sanctum as hexblast mine occultist and am looking into a build to swap to in order to ultimately go 40/40. I’m considering archmage heiro, but not sure if I should go ice nova or spark and how they compare for Uber bosses. Also never got around to playing PBoD when it was op so not sure how it is now for Uber bossing, etc.

I guess my fallback could always just be rerolling into hexblast trickster to get tanky but I’d rather play something different I think.