[Bloodtitan]

i see no reason to side with bodhi even if you are evil. she and here vampires are allies of your main target and they will betray you in the end.
another interesting thing : evil often gets minor quest reward xp so you should ally with the thieves. same xp for quests as bodhi's and you will kill the vampires what gives you a lot more xp than those lousy mighty shadow thieves.