Sentinel

At end of combat, gain control of all creatures blocking this creature for as long as you control this creature.

When this creature dies, destroy all creatures blocking or blocked by it. They can't be regenerated.

2, T: Exile target creature you control. At the beginning of your upkeep, you may sacrifice this land. If you do, return each card exiled with this land to the battlefield under its owner's control.

Prevent all damage that would be dealt to target creature this turn.

Flying At the beginning of your upkeep, sacrifice Nicol Bolas unless you pay UBR. Whenever Nicol Bolas deals damage to an opponent, that player discards their hand.

At the beginning of your upkeep, put a pin counter on this artifact. At the beginning of your end step, if this artifact is untapped, destroy this artifact and it deals damage to you equal to the number of pin counters on it. XX, T: This artifact deals damage equal to the number of pin counters on it to any target. X is the number of pin counters on this artifact.

Flying, trample At the beginning of your upkeep, sacrifice Palladia-Mors unless you pay RGW.

T: Add C. If you control an Urza's Mine and an Urza's Power-Plant, add CCC instead.