The Animus Vitae

You can only use this weapon once per battle. If it hits, the target suffers D3 mortal wounds. If any enemy models are slain by this weapon then, for the remainder of the turn, friendly units with the Power from Pain ability treat the current battle round as being 1 higher than it actually is when determining what bonuses they gain, so long as they remain within 6" of the bearer. This is cumulative with other, similar effects