Yeah, the Necromancer wasn't an Illager in the original CQ and I guess his faction list hasn't been updated. For now let's just say that necromancers are shunned in Illager culture because their magics are considered spooky and unnatural.

WE HATE YOUR MAGICS! (Uses flame throwing magic to obliterate necromancer who isn't even fighting back)

Unless the necromancer is just a n00b and is not correctly raising them from the dead, they just come back and destroy him :p

that is supposed to be like that. necromancer is in a different factions than the illagers

but its a bug that he is assigned as the boss of the wrong faction