Opportunity

4U: Target creature can't be blocked this turn.

This land enters tapped unless you have two or more opponents. T: Add W or U.

1W, Sacrifice this creature: Exile target enchantment.

Whenever an instant or sorcery spell is cast during your turn, this artifact deals damage to any target equal to 1 plus the number of instant and sorcery spells cast before that spell this turn.

T: Choose a player. That player adds one mana of any color they choose.

Whenever this creature or another Warrior your team controls enters, target opponent loses 1 life and you gain 1 life.

This land enters tapped unless you have two or more opponents. T: Add B or R.

Untap this artifact during each other player's untap step. T: A player of your choice adds C.