msem-instigator

{2}, Remove a counter from another permanent you control: Ruthless Monstrosity gets +2/+2 until end of turn.

Pay any amount of life. Look at twice that many cards from the top of your library and put one into your hand. Exile the rest.

Tendrils of Corruption deals X damage to target creature and you gain X life, where X is the number of Swamps you control.

Choose target opponent. Scry 3, then reveal the top card of your library. The chosen player discards an amount of cards equal to that card's mana value. (To scry 3, look at the top three cards of your library, then put any number of them on the bottom of your library and the rest on top in any order.)

Flying
Tribute 2 (As this creature enters, an opponent of your choice may put two +1/+1 counters on it.)
When Tireless Vulture enters, if tribute wasn't paid, each opponent loses 3 life. You gain life equal to the life lost this way.

Menace
Cat creatures you control have menace.
When Basat Priest enters, create a 2/2 white Cat creature token.

Target creature gets +3/+3 until end of turn.

Haste
When Caravan Engulfer enters, creatures you don't control can't block this turn.

Exile target card from your graveyard. You may play it this turn.

Create two 1/1 red and white Sand Warrior creature tokens.

Enchant creature
Enchanted creature gets +2/+2 and can't be blocked as long as defending player controls a Desert.

Reach (This creature can block creatures with flying.)

Haste
Menace (This creature can't be blocked except by two or more creatures.)
{4}{R}{R}: Ferocious Desert-Hunter gets +X/+0 until end of turn, where X is its power.

Fire from Above deals 2 damage to target opponent and each creature with flying that player controls.

Whenever you cast a spell during an opponent's turn, Haughty Priest deals 1 damage to that player.

Haste (This creature can attack and {T} as soon as it comes under your control.)
Mirage {R} (You may cast this spell as though it had flash for its mirage cost. If you do, sacrifice it at the beginning of the next cleanup step.)

Whenever a creature blocks, Heat of Battle deals 1 damage to that creature's controller.

Enchant creature
Enchanted creature gets +2/+0 and has first strike.
Mirage {R} (You may cast this spell as though it had flash for its mirage cost. If you do, sacrifice it at the beginning of the next cleanup step.)

Scry 3, then reveal the top card of your library. Discard your hand, then draw cards equal to that card's mana value.

First strike, haste
When Mounted Marksman enters, it deals 2 damage to target creature you don't control.

Trample
Tribute 3 (As this creature enters, an opponent of your choice may put three +1/+1 counters on it.)
When Rockpounding Saurian enters, if tribute wasn't paid, you may destroy up to one target artifact, up to one target land and up to one target Fortress.

When Sandmouth Dragon enters, another target creature you control gets +3/+0 until end of turn.
Mirage {2}{R} (You may cast this spell as though it had flash for its mirage cost. If you do, sacrifice it at the beginning of the next cleanup step.)

Haste
Sixpod Sprinter can't be blocked except by creatures with flying or reach.

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)

Creatures you control get +1/+0 and attack each turn if able.
As long as you control four or more Mountains, attacking creatures you control get an additional +1/+0 and have first strike.