Major deities like Wee Jas would probably delegate such errants to their servants, but if the DM ok's an actual avatar it'll work too.
[Edit]: In regards to your backstory, how about if it wasn't a divine apparition at all? Your character was brought to unlife unwillingly by a necromancer whom you then killed (I gathered from your other posts). What if a Knight Vindicator (or something the like) of Wee Jas was tracking the necromancer too (since Jasites take dim view on reanimating unwilling targets), and you ran into him?