msem-instigator

{T}, Pay 1 life: Add one mana of any color that a land an opponent controls could produce.

As an additional cost to cast this spell, exile a creature card from your graveyard.
You draw three cards and you lose 3 life.

Enchant creature
Enchanted creature has first strike. (That creature deals combat damage before creatures without first strike.)

Undine Coven gets +1/+1 for each other Merfolk you control.
Whenever you cast a noncreature spell, Undine Coven deals 1 damage to target player or planeswalker.

Return up to two target creature cards with total mana value 4 or less from your graveyard to the battlefield.

Mill four cards, then return any number of creature cards with total mana value 4 or less from your graveyard to the battlefield.

Creatures you control get +2/+0 and have deathtouch as long as ten or more cards are in your graveyard.

Whenever a creature you control dies, you may return all cards that were inscribed onto that creature and all Auras that were attached to that creature to their owners' hands.

Unending Slime enters with X +1/+1 counters on it.
{2}{G}{G}{G}: Return Unending Slime from your graveyard to your hand.

Search your library for up to four basic land cards, reveal them, put them into your hand, then shuffle. You may play an additional land this turn.

Flying
When Unfettered Atrocity enters, destroy target creature or planeswalker.

Unfettered Noble can't be blocked unless defending player pays 3 life, discards a card, or sacrifices a nonland permanent for each creature they control that's blocking it.
Sacrifice a nonland permanent: Unfettered Noble gains indestructible until end of turn.

Exile target nonland permanent if its mana value is less than or equal to the number of creatures you control.
Lifecycle {3} ({3}, Discard this card: Create two tapped 1/1 colorless Elemental creature tokens.)

As an additional cost to cast this spell, exile X cards from your graveyard.
Create X tapped 2/2 black Zombie creature tokens.

Menace
{3}{B}, Discard a card: Unhallowed Singers gets +3/+0 until end of turn. Whenever it deals combat damage to a player this turn, they discard a card.

Destroy target creature with total power and toughness 8 or less.

Target creature can't block until end of turn. If that creature had a Steed attached to it, unattach that Steed and it can't block until end of turn.
Draw a card.

{T}: Add one mana of any color.
{T}, Sacrifice Unicorn of the Vale: Add three mana of any one color.

Whenever you cast a noncreature spell, create a 1/1 colorless Construct artifact creature token.

Look at the top six cards of your library. Put up to two creature cards with mana value 3 or less from among them onto the battlefield. Put the rest on the bottom of your library in a random order. Then you gain 1 life for each Angel, Demon, Faerie, and/or Spirit you control.

When United in Battle enters, look at the top six cards of your library. You may reveal a Dwarf or Elf card from among them and put it into your hand. Put the rest on the bottom in a random order.
Whenever a Dwarf or Elf you control enters, put a +1/+1 counter on it.

Other creatures you control get +1/+0.
At the beginning of combat on your turn, create a 1/1 red Human creature token with haste.

Creatures you control have base power 4 and gain trample until end of turn.

As Unlikely Growth enters, choose grow or maintain.
Whenever a land you control enters,
• Grow — Put a +1/+1 counter on target creature you control.
• Maintain — Target creature you control gains trample and indestructible until end of turn.

Menace
Foresight — Whenever you draw your second card each turn, target player loses 2 life and you gain 2 life.