Brávellir Battlefield

Bravellir Battlefield enters the battlefield tapped, and does not untap during your untap step.
Whenever creatures you control have dealt ten or more combat damage this turn, you may untap Bravellir Battlefield.
{w},{t}: You may put all creatures cards you own onto the battlefield that were put into a graveyard from the battlefield this turn.
{t}: (Add {w} to your mana pool.)