I agree that necromancy is quite cheap background, you get alot free necromancy spells that way :P. Also one background gave EXTRA points spend on some material things and backgrounds (it was liege as I recall). But if you want toast Deathlord dependant Abyssals ass, then ask more of him than usual, send him sucide levle missions or punihs him more harshly in failures and any possible sing of betrayal etc.