Beating Doppleganger with Monk

I was hoping someone could give me some hints on beating the doppleganger with a monk. I didn't want to use my secondary class (necro), since I will be changing it soon. Thx.

You'll get a full refund of all attribute points spent on nec lines upon switching, all the more reason to use your nec secondary to beat it.

Take no healing spells, fill up with as many useless health sacrifice skills as you can, and bring scourge sacrifice along with a smite spell.

what i did (mo/mes) is bring as many enchantments along so he had mana DEgen, then i just cast things like empathy on him and let him kill himself. Although this did take me 5-15 tries to get it right

lol, the tactic is so simple, unequip all skills, have no skills with you, and then take a weapon that fires something, staff or wand, just dodge his arrows and shoot at him. You win easily and do it under 50secs (for bonus)