Dark Regulus?
Regulus is on the dark side in a pantheon match
from
Demigod Forums
I joined a pantheon game and got quite a shock when i saw what looked like erebus carrying a crossbow.
Turns out regulus doesn't like the forces of light anymore
http://i131.photobucket.com/albums/p294/smodge13/DemigodPantheon.jpg
I assume this is a bug.