Okay, I have a couple of ideas, one of which would most definitely require GM approval as I noted in the Int Check we have a necromancy ban in place. But I will make my humble petition nonetheless.

So, my first idea is for a mage, who was in unrequited love with Octavia Ravenwood. When she died, he became obsessed with the possibility of true resurrection and plunged headfirst into a misguided exploration of forbidden magicks and reviled necromancy, much to the dismay and horror of his former comrades.

Idea two, a hardened sellsword gone to seed. Used to be one of the best blades around, but has spent all his time trading on his heroic reputation to get plastered and is basically a washed up drunk by this point. 

I have another idea about some guy who's like literally given up being an adventurer and retired to live on a farm with his wife and kids, but it don't know if it really works, as 'I don't want to be here' doesn't make too much of a fun character motivation.