Board Thread:Warhammer 40k General Discussion/@comment-5.65.81.205-20131020155613/@comment-34716664-20180218193528

The only way to truly kill Daemons is to kill off the emotions that created their Chaos God. So basically the only way to get rid of Daemons is to get rid of the Ruinous Powers.

But yes, Daemons can kill their kin, since they are part of their Chaos God.