, Discard a card: Crashing Centaur gains trample until end of turn.Threshold — As long as seven or more cards are in your graveyard, Crashing Centaur gets +2/+2 and has shroud. (It can't be the target of spells or abilities.)
Discard any number of cards. Target player reveals their hand, then you choose a nonland card from it for each card discarded this way. That player discards those cards.
, Sacrifice a creature: Target creature gets -2/-2 until end of turn., Exile a creature card from your graveyard: Target creature gets -2/-2 until end of turn.
Volley of Boulders deals 6 damage divided as you choose among any number of targets.Flashback (You may cast this card from your graveyard for its flashback cost. Then exile it.)
, Exile Shifty Doppelganger: You may put a creature card from your hand onto the battlefield. If you do, that creature gains haste until end of turn. At the beginning of the next end step, sacrifice that creature. If you do, return Shifty Doppelganger to the battlefield.
: Add . Nomad Stadium deals 1 damage to you.Threshold — , , Sacrifice Nomad Stadium: You gain 4 life. Activate only if seven or more cards are in your graveyard.
Creatures you control get +3/+3 and gain trample until end of turn. (Each of those creatures can deal excess combat damage to the player or planeswalker it's attacking.)