Haven't gotten to play either of these yet, but I might someday.

1. Aberrant Mind sorcerer, race tbd. Basically, was an eldritch abomination who got bored, and turned itself into a mortal for a change of pace. We're talking "Had 30 Int and Wis" levels of abomination. So now it's stuck in a limited mortal form with all this knowledge, and no ability to use it. Can't even pronounce its own name anymore.

2. Incubus/succubus (reflavored tiefling) paladin of redemption. Nommed on the wrong soul and got purified, and now trying to atone for their past misdeeds. They're virtually starving themselves, which is why they're using a tiefling statblock instead of the normal one, only having the ability to switch sex, and the draining kiss that they never use save to keep themselves alive with a consenting travelling partner.