msem-instigator

Create a 1/1 white Peasant creature token if you control a Citizen or Peasant. Then Byron's Reprisal deals damage equal to the number of creatures you control to up to one target creature or planeswalker.

Whenever target creature deals combat damage to a player this turn, create a token that's a copy of it.

{X}, {T}, Sacrifice Macabre Ruins: Target creature gets -X/-X until end of turn.

Exile target creature, then return it to the battlefield under your control. Then sacrifice it.

Destroy target artifact or enchantment.
Cycling {2} ({2}, Discard this card: Draw a card.)

When Holy War enters, create three 1/1 white Cleric creature tokens.
Creature tokens you control have first strike and lifelink.

Trample
Whenever a creature dies, put a +1/+1 counter on Venomclaw Skitterer. You gain 1 life.

Wu Xing (Add effects based on the number of colors of mana spent to cast this spell.)
1 | Battle of Principles deals X damage to any target.
5 | When a creature or planeswalker dealt damage this way dies this turn, return it to the battlefield under your control.

Flying
Whenever another artifact you control enters, Filigree Drake gets +1/+1 until end of turn.

All creatures get -2/-2 until end of turn. Remove two loyalty counters from each planeswalker.

Target creature gets +3/+3 until end of turn. If this spell was foretold, it gets +5/+5 until end of turn instead.
Foretell {1}{G} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

You may return a land you control to its owner's hand rather than pay this spell's mana cost.
Northern Express Line enters tapped.
{T}: Add {U}.

{T}: Add {C}.
{T}: Add one mana of any color that a basic land you control could produce.

Dawnlit Battlefield enters tapped.
{T}: Add {R} or {W}.
{2}{R}{W}: Until end of turn, Dawnlit Battlefield becomes a 4/2 red and white Warrior creature with with “This creature has first strike as long as it's attacking” and “Whenever this creature attacks or blocks, torment yourself.” It's still a land. (To torment yourself, lose 3 life unless you discard a card or sacrifice a nonland permanent.)

Enchant creature
When Prophet's Paranoia enters, tap enchanted creature, then scry 2.
Enchanted creature loses all abilities and doesn't untap during its controller's untap step.

Enchant land
When Contested Discovery enters and at the beginning of your upkeep, untap enchanted land. You gain control of that land until end of turn.

Look at the top six cards of your library. Put up to two creature cards with total mana value 4 or less from among them onto the battlefield and the rest on the bottom of your library in any order.
Ferocious — If you control a creature with power 4 or greater, put a +1/+1 counter on each creature you control.

When Poisoned Shiv enters, destroy target creature or planeswalker.
Equipped creature gets +2/+0 and has deathtouch.
Equip {2}

Enchant creature
Spirited (When this enters, you may activate one of its activated abilities without paying its cost.)
{1}: Enchanted creature can't attack or block this turn.

Deathtouch
When Scion of Desolation enters, put target creature card with mana value 3 or less from a graveyard onto the battlefield under your control.
Whenever a Swamp you control enters, you may aetherize Scion of Desolation. (To aetherize, create a token that's a copy of it, then exile that token.)

Trample
Whenever you cast a noncreature spell, put a +1/+1 counter on Coralhide Wurm.

Each opponent sacrifices a creature, then loses 4 life. You return a creature card from your graveyard to your hand, then gain 4 life.

Vigilance
When Tortle Guard enters, it explores. (Reveal the top card of your library. Put it into your hand if it's a land. Otherwise, put a +1/+1 counter on this creature, then you may put that card in your graveyard.)

Nizev Sanctuary enters tapped.
Satrapies you control have “{T}: Add {U} or {R}.”

When Mountain-Western Inventor enters, you may return target artifact card from your graveyard to your hand.
{1}, Sacrifice an artifact: Target creature can't block or be blocked this turn.