How? If he didn't have the resists or I could prep even one potion - you know the one - I think I could manage. Maybe if Retaliate wasn't an issue. Closest I can think of is maybe a Monk stacking 75% physical resist and getting Martyr Wraps and HALPMEH by scumming. Once entirely out of mana, worship Dracul and start sucking up blood pools. Possibly a Dwarf Monk - get those HP high to get a little extra healing off the blood pools/more efficient potions. Basically drag out the fight as long as possible to stack double digit corrosion.
I've finished all the puzzles (was actually slightly disappointed I didn't get orc or goblin puzzles) and I've got all the Silver class challenges beaten except Paladin, which seems to refuse to unlock for some reason. Actually that works in my favour ATM since it's one less item that isn't Martyr Wraps that can spawn in the shops, if I have to go with this strategy.