msem-instigator

Assault {G} (Whenever this attacks, if it has no +1/+1 counters on it, you may pay its assault cost to put a +1/+1 counter on it.)
Whenever a creature you control assaults, it gains indestructible until end of turn.

Vanishing 1 (This creature enters the battlefield with a time counter on it. At the beginning of your upkeep, remove a time counter from it. When the last is removed, sacrifice it.)
When Waning Behemoth enters the battlefield, you may pay {X}. If you do, put X time counters on it.

Augmented — When you cast Want It All, if you've spent {W}{U}{B}{R}{G} to cast spells this turn, copy Want It All for each other spell cast this turn.
Shuffle your library. Then exile the top card of your library. You may play it without paying its mana cost.

Legacy (You may play this side of this card only from your graveyard. Exile it if it would leave the battlefield or not resolve.)
Whenever you attack, you may discard up to X cards, where X is the number of attacking creatures you control. Draw a card for each card discarded this way.

Whenever War Priest of Bahet deals combat damage to a player, purge. (Exile two cards that share a type from graveyards. If you do, draw a card.)

Protection from instants and from sorceries
When Warbringer Titan enters the battlefield or attacks, create two 1/1 white Soldier creature tokens with melee. (Whenever that creature attacks, it gets +1/+1 until end of turn for each opponent you attacked this combat.)

Vigilance
Whenever Warchief of the Folded Fan attacks, invigorate 2. (Choose a creature with the least power among creatures you control and put two +1/+1 counters on it.)

Whenever you cast an Elf spell, create a 1/1 green Elf Druid creature token.
Tap four untapped Druids you control: Destroy target artifact or enchantment.

Flying
If Warden of Distortion would die, you may exile a creature card from your graveyard. If you do, Warden of Distortion becomes a copy of that creature, except it's a 4/4 Nightmare Dragon and it has flying and this ability. It gains indestructible until end of turn.

When Warden of the Dead enters the battlefield, you draw a card and you lose 1 life.
When Warden of the Dead dies, conjure three cards named Warden of the Dead and shuffle them into your main library. For the rest of the game, you may cast spells named Warden of the Dead without paying their mana costs.

Flying
Morph {2}{W}{W} (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 you turn Wardwing Seraph face up, untap it.

Flying, haste
Whenever Warfury Dragon becomes enchanted or equipped, monstrosity 2. (If this creature isn't monstrous, put two +1/+1 counters on it and it becomes monstrous.)

Distorted (This creature can be blocked by tapped creatures but not untapped creatures.)

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.

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

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

Flying (This creature can't be blocked except by creatures with flying or reach.)
Vigilance (Attacking doesn't cause this creature to tap.)

Remove all -1/-1 counters from target creature. That creature gets +3/+3 and gains trample until end of turn.

Slipstream (This creature can't be blocked as long as only creatures with slipstream are attacking.)
{3}{U}: Target creature gains slipstream until end of turn.

Create two Idol tokens, then counter target spell unless its controller pays {1} for each Idol you control. (They're artifacts with “{1}, Sacrifice this artifact: Put a +1/+1 counter on target creature. Activate only as a sorcery.”)

As Wayward Wanderers enters, you may have it become X/X with ward {X} and “Other creatures you control have base power and toughness X/X.”
{1}{G}: Return Wayward Wanderers to its owner's hand.

Create an 8/8 blue Kraken creature token.
{2}{U}, Discard Wealth of the Flood: Create a Treasure token. Scry 2.

{2}{R}: Creatures you control get +1/+0 until end of turn.
{1}{G}: Creatures you control gain trample until end of turn.

When Weaver of Mists enters the battlefield, substantiate target card in your graveyard. (Put it onto the battlefield face down as a 2/2 creature. You may turn it face up and cast it at any time for its mana cost if it isn't a creature.)
Spells you cast from anywhere other than your hand cost {1} less to cast.