Reach Valhalla

Whenever a creature you control dies, you may
pay {2}. If you do, put a Valhalla counter on
Reach Valhalla.
If there are 10 or more Valhalla counters on
Reach Valhalla, return all creatures from your graveyard to the battlefield.
All Viking creatures you control get +1/+1 and
have Berserker. (This creature may attack target creature an opponent controls instead attacking
players.)