msem-instigator

Assault {X}{R}{R} (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.)
Other Elementals you control get +1/+0.
When Unbound Annihilus assaults, create X 1/1 red Elemental creature tokens that are tapped and attacking.

When Unbound Expanse enters, if an opponent controls more lands than you, create a Plains token. (It's a basic land with “{T}: Add {W}.”)
{1}{W}, Sacrifice Unbound Expanse: Exile each nonland permanent you control, then return those cards to the battlefield under your control.

Escalate—Return another spell you control to its owner's hand. (Pay this cost for each mode chosen beyond the first.)
Choose one or both —
• Draw a card.
• Draw a card.

Whenever you copy an instant or sorcery spell, you may pay {1}{U}. If you do, draw a card.
Whenever you cast an instant or sorcery spell, you may pay {1}{R}. If you do, Unbound Researchers deals 2 damage to target player or planeswalker.

Whenever you cast another creature spell, create a 1/1 green and white Elk Spirit creature token.
As long as you control five or more Elk, creatures you control get +3/+3 and have trample.

Up to two target creatures each get -3/-0 until end of turn. Tap those creatures. They don't untap during their controller's next untap step.

Target creature gets +1/+0 and gains indestructible until end of turn. Draw a card if you control an Angel, Demon, Faerie or Spirit.

Whenever Unbudging Badger attacks, if its power is 4 or greater, it gains trample until end of turn.

Destroy target artifact or enchantment. You gain life equal to its mana value.

Target opponent sacrifices half the permanents they control, rounded down.

When Unburdening Priest enters, you may exile any number of creatures you control not named Unburdening Priest, then return those cards to the battlefield under your control.

Search your library for a permanent card with mana value X or less, reveal it, put it into your hand, then shuffle.

Target creature gets +1/+1 and gains double strike until end of turn. (That creature deals both first-strike and regular combat damage.)

Whenever Uncanny Allocator enters or attacks, give any number of permanents and/or players with counters on them another counter of each kind already there.

Spend only mana produced by Treasures to cast spells.
{2}, Discard a card: Create two Treasure tokens.

Unceasing Flames deals X damage to any target, where X is 2 plus the number of cards named Unceasing Flames in your graveyard.
Conjure three cards named Unceasing Flames and shuffle them into your main library.

Put two -1/-1 counters on target creature.
Agonize (You may cast this card from your graveyard by putting a -1/-1 counter on a creature you control in addition to paying its other costs. Then exile this card.)

This spell costs {2} less to cast if you control a Scout.
Search your library for up to two basic land cards, reveal those cards, and put one onto the battlefield tapped and the other into your hand, then shuffle.

Uncharted Haven enters tapped.
As Uncharted Haven enters, choose a color.
{T}: Add one mana of the chosen color.

Hexproof
When Uncharted Leviathan enters, target creature can't be blocked this turn.

Creatures your opponents control get -2/-0 until end of turn.
Draw a card.

Whenever a creature you control is dealt damage, put a +1/+1 counter on that creature.

Enspirit (As you cast this spell, you may exile a nonenchantment creature you control until this leaves the battlefield or fails to resolve. Reduce this spell's cost by the exiled card's mana value.)
Deathtouch

Target creature can't be blocked this turn.
Compose (Then if you cast this from your hand, exile it and create a Saga token with “r3—You may cast a copy of this card from exile without paying its mana cost.”)

Look at the top two cards of your library. Put one of them into your hand, then you may have any number of players each mill three cards.