Are there any wizard tricks to killing this thing?
On my previous character (cleric) I was fine with throwing up all the damage enhancing buffs, slapping on an off-hand weapon, and going to grab a drink and stretch my legs.
My new Wizard on the other hand, even taking into account hitting the gateway on a 2+, still can't deal a whole load of damage to it. The portal has loads of resistances/immunities, even more HP, high SR, great saves, and crit immunity. It has enough melee damage reduction that I generally only hurt it with the bonus damage die on my weapons (thankfully, the 'good' damage works).
As far as I can see spell-wise, I can only land Disintegrates on it (which it makes the save against), so killing it with one SP bar isn't really happening. Being an inanimate object with ridiculous SR, saves, and resists, it's immune to everything else that I've tried.
Should I just stick to meleeing it, or perhaps even skip it entirely? If it ends up taking me upside of 20 minutes of melee to kill then it's hardly efficient in chests/time.