It took me a long time to finally make it! Swarm intelligence + hostile champions + badder bosses, with a sniper.
I was lucky to get a projecting bow and a brimstone armor (plate). I don’t know if I’d have survived the burning fist + dark fist combo without it.
Just keep trying and you’ll get there. It took me many, many games, and I still lose much more than I win with two challenges. Sometimes it feels like a whole different game, once you enable a couple of challenges.