Dont see anything overpowered here, the perk is in at slvl100, and the atronach stone has to be found, and prohibits the use of other stones. Also it doesnt negate damage, which means one can still be one-shotted, if absorb is the only protection. I'd choose 85% magic resist any day over absorb tbh. 100%.. Bretons have it too, i dont see everyone playing Bretons.
I don't think you understand, magic does no damage what so ever, I absorb magicka for every magic that hits me, even poison. From a strength perspective why the hell would you want resist that can't hit 100% over absorb that can, considering you take no damage and absorb all the magicka.
I know it's at level 100, took me a while to get there. I've realised now its down to the necro vamp thing though, otherwise you would be stuck with the soft cap of 80%, 100% for 60 seconds using the breton power.
One shotted? From melee I still take the same damage, but thats irrelevant, I don't think you understand.