My friend and I picked up DD1 again after not having played it since, well, close to when it came out. We're playing Redux. We've finished all the main maps (not DLC) on Insane, leveled up to level 74 via Glitterhelm, and after farming some basic mythics, have finished the base maps in nightmare up until the dragon stage, which we're pretty sure we're going to get crushed on, given how difficult the other bosses were.

But we feel like we're plateauing and not entirely sure what to do next to get better gear and level up more. Goblin Copters in particular give us a LOT of trouble if harpoons/archers don't shoot down the ogres into the abyss.

I'm playing a huntress, monk, and squire, and he's playing a DPS jester and summoner, and also has a series EV. I only have the Eternia Shards DLC (and anything else that's free). Most of my stats are around 300-400 with matching sets. Any thoughts on what we should focus on to make the best progression?