An artifact often gifted to Barbarians which provides magic resistance and half spell damage but prevents Pw from regenerating. Or assign these properties to the Heart of Ahriman, which makes it good for Barbarians as they rarely cast spells.

Chargeable ring that reduces incoming damage (perhaps by half, not triggering if half physical or half spell damage applies from some other source) but may lose a charge every time you take damage.

Split curse resistance off from magic resistance. Curse resistance is granted only as an extrinsic by a couple of artifacts, including Magicbane, and ‘‘maybe’’ some mundane item that isn’t any good otherwise (a mummy wrapping?), and behaves like Magicbane’s curse resistance does currently (“You feel a black aura surround the [item].”) Half spell damage without curse resistance no longer helps limit the number of cursed items, and a curse may still manage to bypass resistance, with current probabilities. There could also be an amulet versus curses.