I 3*'d it on my first try, but maybe not an optimal way. I didn't realize that there was double damage throughout the dungeon against taunters.
However, I did it with Furnace 3*, Therand, Dag, and Yasmin. The key thing was that I burned 3 energy pots early to boost Furnace's HP to the point that he could survive the extra damage. Dag only attacked when not using his first ability on himself and the third on Furnace. By the boss room, he was taking very little damage compared to his HP.
Also, I never used Yasmin for healing. A couple times I used Aegis on Furnace just to eliminate a hit. MK may be a better option.
If I was to redo it, I might try a bulky team like Igo, OE, Auggie, and Nub. Undead might work but my Zomm is underpowered so not for me.
Formerly of the Potato Army. I've mostly quit playing DB. However, I can be reach in Book of Heroes (in game or forum) as bbbb.