Board Thread:Warhammer 40k General Discussion/@comment-212.10.157.234-20131206235526/@comment-25177957-20140802092433

Well if Lucius the Eternal must be killed by a being who takes no pleasure in it, the best bet would for him to meet his death at the hands of a Necron overlord or Tyranid creature, as both of them feel no emotions. A Grey Knight could also do it possibly, and one that could repeat the soul destruction bolt that the Emperor used on Horus.