Just tested this build out on Den of Danger, I finished the dungeon with:
246 damage. (112 base + 120%)
65% magic res.
30% physical res.
-5 damage reduction.
So basically this build takes advantage of god switching from Taurog to Glowing Guardian.
Pick Orc Berserker and equip yourself with Whuurgarbl sword (optional). Once in the dungeon worship Taurog and grab all the items except the helm (I got the helm in this game but it's actually unnecessary as enlightenment+Berserker resist already gives you max magic resist). Once you have the items you need, switch to GG, convert all your potions and take humility. By this stage with your ridiculous damage and stats you can own pretty much anything 2-3 levels higher than you and sanctify everything else, so you'll be getting plenty of piety. Grab enlightenment and then it's pretty much good game from there - most bosses you'll be able to 1-2 shot, this one took 3 hits because he had 60% physical resist.
The great thing about this build is it's still pretty powerful if either Glowing Guardian or Taurog is unavailable in your dungeon, so you're not completely screwed if you get a bad Altar roll. Going pure Taurog you can just skip the helm or shield (you won't have the inventory space with the Whurrgarbl) and use potions for healing instead of the GG healing. Going pure GG you can just buy items from shops to help with your damage if you need to.
Edit: After my second run through with this build, I'm now thinking that it's better to keep your health potions and only convert your mana ones, that way you'll still be able to have enough piety for enlightenment, but you have more healing at the end if you need it - taking a 10 piety hit from using a healh potion is better than spending 20 on a heal, you might even want to switch back to Taurog at the end to avoid any penalty.
Edit2: This works brilliantly with Human Monk as well, you can skip the helm and armor - take in a blacksmith item or buy something from a shop instead.