Aligned Hedron Network [Battle for Zendikar Prerelease Promos] Hydra Avatar Centaur Chieftain has "When Centaur

Centaur Chieftain has "When Centaur Chieftain enters the battlefield

Set: Alpha Edition Type: Artifact Creature — Beast Rarity: Rare Cost: {6} Clockwork Beast enters the battlefield with seven +1/+0 counters on it

Set: Amonkhet Invocations Type: Sorcery Rarity: Mythic Cost: {B}{B}{B} Search your library and graveyard for five cards and exile the rest

sacrifice The Gitrog Monster unless you sacrifice a land

Aligned Hedron Network [Battle for Zendikar Prerelease Promos] Hydra Avatar Centaur Chieftain has "When CentaurSet: Battle for Zendikar Prerelease Promos Type: Artifact Rarity: Rare Cost: {4} When Aligned Hedron Network enters the battlefield, exile all creatures with power 5 or greater until Aligned Hedron Network leaves the battlefield. (Those creatures return under their owners' control.) The last hedron slotted into place, locking Ulamog in an infinite loop of binding energy.