My current favorite build is SpEE of Vehumet moving to Ice magic mid-late game.
My current game generated a Cloak of the Thief: +0 Quiet, SInv, Stealth+. Lacking anything else for cloak slot I put it on. I’ve got this a few times with my stabbers and while it was nice it didn’t really seem amazing.
But with my Ice mage? It’s amazing. Polar Vortex to clear the Vault:5 entrance doesn’t draw any adds. I can cast Polar Vortex in the Slime Pits, and monsters in LOS but outside the storm will actually sleep through it.
It’s let me spam Permafrost Eruption and Ozocubu’s Refrigeration with basically no regard for adds whatsoever.
For me this would be a negative. I love how loud noises bring enemies straight into a zone that I control. That way I can camp the stairs and destroy things from a distance.
I’m a bit surprised it is as effective as you say it is - and I have to admit that being able to cast spells and have monsters in LOS stay asleep seems like it might be a bug, or overtuned feature.
This doesn’t require Quiet to happen. Just with pure stealth, I’ve occasionally cast Stone Arrow in one direction and had monsters in the other direction stay asleep. Or cast Sandblast and have monsters relatively near the target stay asleep if it’s a one-shot. And I fairly regularly have monsters wander off in the wrong direction because I wake them up with Freezing Cloud but they don’t notice me.
It was just super wild to see this happen with something as loud as Polar Vortex.