Sentinel's Mark

Exile target creature with power 4 or greater.

Flash Flying When this creature enters, until end of turn, damage that would reduce your life total to less than 1 reduces it to 1 instead. 4WW, Exile this card from your graveyard: Your life total becomes 10.

Whenever a creature you control attacks alone, it gets +X/+X until end of turn, where X is the number of creatures you control.

Flying When this creature enters, you gain 2 life for each Gate you control.

Target creature gets +2/+2 until end of turn. Addendum — If you cast this spell during your main phase, that creature gains flying until end of turn.

When this creature enters, creatures you control get +1/+1 until end of turn.

Flying

Destroy target artifact or enchantment. Scry 1.