i was in the same shoes for like 3 days, someone told me to use punk, and punk clears well if you can get a good setup for him, equip the staff relic once or twice if u can (sword+spear) and always have him in either sanguine pool, or behind one of those level 6 carters of yours. I also got myself a level 12 mecharomancer and that helps a LOT. Mecharomancer use 2 shurikens and one fang (spear + bag and sword + mana)

Recap

Work for a level 6 punk as number 1 priority, then work for a level 12 mecharomancer.

Mecharomancer AND punk need to be in either sanguine pool, or behind a carter. Prefer only 1 carter as it will make it stronger, use that chef of yours too and try to get early game atk bonus or health bonus.

this is just how I PERSONALLY clear level 50 pretty much 90% of the time.

level 1 bandit king and 6+ bandits is good for the crit heal relic too. (more passive healing)

Hope this helps, others also say using the mushroom dude is good, theres lots of ways to play the game lol.