msem-instigator

Each creature with power greater than its toughness doesn't untap during its controller's untap step.

Equipped creature gets +1/+1.
As long as equipped creature is a Warrior, it has first strike.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Whenever equipped creature attacks or blocks, it gets +3/+3 and gains hexproof until end of turn.
Equip {1}

Enchant creature
When Warrior's Discipline enters, put a +1/+1 counter on enchanted creature.
Whenever enchanted creature deals combat damage to a player, double the number of +1/+1 counters on it.

Invigorate 1, then untap each creature you control with a +1/+1 counter on it. (Choose a creature with the least power among creatures you control and put a +1/+1 counter on it.)

When Warrior's Perspective enters, invigorate 1. (Choose a creature with the least power among creatures you control and put a +1/+1 counter on it.)
Whenever a creature you control with a +1/+1 counter on it becomes tapped, you may draw a card. If you do, discard a card.

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.

You may put a Dragon creature card from your hand onto the battlefield. That creature gains haste until end of turn. Return it to its owner's hand at the beginning of the next end step.

Flying, lifelink
Legendary creatures you control get +1/+1.

Enchant creature
Enchanted creature is a blue Frog with base power and toughness 1/1 and loses all other card types, creature types and abilities.

Trample, prowess
You may exert Wartorn Veteran as it attacks. When you do, double its power until end of turn. (An exerted creature won't untap during your next untap step.)

Wary Rider has first strike as long as its attacking.
Wary Rider gets +1/+0 as long as you control two or more other creatures.

Hexproof
When Wary Watchkeeper enters, target player mills three cards.

Counter target activated or triggered ability.
Metamorph {U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up and cast it at any time for its metamorph cost.)

Haste
When Wasteland Rabblerousers enters, creatures your opponents control with power X or less can't block this turn, where X is the number of Deserts you control.

Trample
When Wasteland Ravagers enters, you may sacrifice a land or exile a land card from your graveyard. If you do, creatures you control get +1/+0 and gain haste until end of turn.

First strike
Wither (This deals damage to creatures in the form of -1/-1 counters.)

Advance {3} (Cast this for {3} to advance it as it enters. {3}: Advance this as a sorcery.)
Whenever Wastes Scrambler advances, put your choice of a +1/+1, first strike, menace, trample, or vigilance counter on it. If {R}{W}{B} was spent to advance it, repeat this process twice.
Crew 1

Trample, haste
Defiance (Whenever this creature takes damage, if it survives and wasn't defiant, put a +1/+1 counter on it and it becomes defiant.)
Whenever Wastewolf attacks, it deals 1 damage to any other target.

Whenever Wasting Soul attacks or blocks, sacrifice a creature, then put two +1/+1 counters on Wasting Soul.

Whenever Watch Me Burn enters or another source you control deals noncombat damage, put an ignition counter on Watch Me Burn. Then it deals damage equal to the number of ignition counters on it to each opponent.

Put target nonland permanent on top of its owner's library.

Target player mills two cards.
Draw a card.
Coalesce {6}{U} (You may cast this from your graveyard for {6}{U}. If you do, it enters as a Horror creature after it resolves. Exile it if it would leave the battlefield or not resolve.)

Creature tokens you control have vigilance.
Whenever Watch of the Dead or another enchantment you control enters, create a 2/2 black Zombie creature token.