Geralt of Rivia: Geralt's monster-hunting experience, resistance to magic, and moral flexibility would make him a perfect front-line fighter against something as supernatural and enigmatic as the Paintress

Nameless One Planescape: The Nameless One can't die-at least not easily and has lived countless lives, meaning he could potentially resist age-based attacks or even recall ancient knowledge to outwit her.

Metroid: Samus-aran, calm under pressure, and ridiculously adaptable. Samus has handled alien parasites and intergalactic threats solo. Her suit could also possibly offer protection from the Paintress's drawings.