Legions

Whenever another nontoken Elf enters the battlefield, you may create a 1/1 green Insect creature token.

{T}: Add X mana of any one color, where X is the number of Elves on the battlefield.

Whenever a Sliver deals combat damage to a player, its controller may create a 1/1 colorless Sliver creature token.

Slivers can't be blocked except by Slivers.

Untap all permanents you control during each other player's untap step.

All Slivers have "{T}: Regenerate target Sliver."

When Goblin Firebug leaves the battlefield, sacrifice a land.

Whenever Vile Deacon attacks, it gets +X/+X until end of turn, where X is the number of Clerics on the battlefield.

At the beginning of each player's upkeep, that player mills X cards, where X is the number of cards in their hand.

Flying Creatures can't attack you unless their controller pays {2} for each creature they control that's attacking you.

Cycling {3} ({3}, Discard this card: Draw a card.)

As long as you control a Beast, Skirk Outrider gets +2/+2 and has trample.

{7}{R}: Flamewave Invoker deals 5 damage to target player or planeswalker.

Flying Morph {3}{B} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)

All Slivers have "{1}: This permanent becomes the creature type of your choice in addition to its other types until end of turn."

Flying {1}: Mistform Seaswift becomes the creature type of your choice until end of turn. Morph {1}{U} (You may cast this card face down as a 2/2 c...

{T}: Target creature gets +X/+X until end of turn, where X is the number of Elves on the battlefield.

Cycling {1}{R} ({1}{R}, Discard this card: Draw a card.) When you cycle Gempalm Incinerator, you may have it deal X damage to target creature, wher...

Haste Sacrifice a Goblin: Clickslither gets +2/+2 and gains trample until end of turn.

When Phage the Untouchable enters the battlefield, if you didn't cast it from your hand, you lose the game. Whenever Phage deals combat damage to ...

Morph {1}{U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.) When Willbender is turned f...

{3}{W}, Exile Planar Guide: Exile all creatures. At the beginning of the next end step, return those cards to the battlefield under their owners' c...

Amplify 3 (As this creature enters the battlefield, put three +1/+1 counters on it for each Dragon card you reveal in your hand.) Flying {T}: Kilnm...

Whenever Goblin Assassin or another Goblin enters the battlefield, each player flips a coin. Each player whose coin comes up tails sacrifices a cre...