Valkyrie of Raging Deaths

Whenever a creature you control dies that was dealt combat damage by a creature an opponent controls this turn you may put a corpse counter on Valkyrie of Raging Deaths and lose 1 life.
As long as Valkyrie of Raging Deaths has three or more corpse counters it has flying and +1/+1. As long as it has six or more it has trample and +2/+1. As long as it has ten or more it has lifelink