msem-instigator

Enchant opponent
Enchanted player plays with the top card of their library revealed.
Whenever enchanted player casts a spell, you may have them mill a card.

Enchant creature
Enchanted creature gets +3/+1 and has haste.

First strike, trample
Death knell — Return a permanent card with mana value less than X from your graveyard to the battlefield, where X is the mana value of the last creature that died this turn. (As a creature you control dies, trigger one death knell of that creature or another permanent you control.)

Germinate, then creatures you control that are Saprolings or have counters on them gain indestructible until end of turn. (To germinate, put a +1/+1 counter on a creature or create a 1/1 green Saproling creature token.)

Menace
Sacrifice another creature: Corpulent Gibberer deals 1 damage to any target.
Evoke {1}{R} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters.)

Equipped creature has “Whenever this creature attacks or blocks, choose a creature card in your graveyard. This creature gets +X/+Y until end of turn, where X is that card's power and Y is its toughness.”
Equip {2}

Haste
At the beginning of your upkeep, sacrifice Ember of Ancient Infernos unless you pay {R}.

Other Citizens and Peasants you control get +1/+1.
{2}{G/W}: Look at the top five cards of your library. You may reveal a Citizen or Peasant card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

When Abura-no-Oni enters, target player mills two cards.

Reach
Whenever you cast a spell with mana value 5 or greater, Reaper Squad deals 3 damage to target player or planeswalker.

Reach
{G}, {T}: Swiftshot Sniper deals damage equal to its power to each creature with flying.
{2}{G}: Swiftshot Sniper gets +2/+2 until end of turn. Activate no more than twice each turn.

(Transform this if it's not attached to a creature. Pay {4}{G} as a sorcery to unattach it.)
Enchant creature you control
Herdstrider's rider gets +1/+1 for each land you control and has trample.
Whenever Herdstrider's rider attacks, create an X/X green Elephant creature token with trample that's tapped and attacking, where X is that creature's power. Exile that token at the end of combat.

Target creature you control gets +1/+0 until end of turn. It fights up to one target creature you don't control. (Each deals damage equal to its power to the other.)

Whenever an artifact you control enters, you may put a progress counter on Spectacle of Innovation.
[progress 1+] Artifact creatures you control get +1/+1.
[progress 3+] Artifact creatures you control have flying and hexproof.
Artifact creatures you control have flying and hexproof.

Enchant creature
Enchanted creature can't attack, block, or crew Vehicles.

Enchant creature
Enchanted creature has distorted. (This creature can be blocked by tapped creatures but not untapped creatures.)
{1}{W}: Tap enchanted creature.

Exile up to X target instant and/or sorcery cards with total mana value X or less from your graveyard. You may cast a copy of each card exiled this way without paying its mana cost. Exile Total Recall.

When Dream Keeper enters, each player conjures a card named Fatigue and puts it on top of their library. (It's a colorless sorcery that costs {2} with “Draw a card.”)
Whenever a player draws a card except the first one they draw in each of their draw steps, each opponent mills a card.

The “legend rule” doesn't apply to artifacts and enchantments you control.
Equipped creature gets +1/+1 for each artifact and/or enchantment you control.
Equip {2}

At the beginning of your upkeep, return target enchantment card from your graveyard to your hand.
Whenever Reflect on Serenity or another enchantment you control enters or leaves the battlefield, each opponent loses 1 life and you gain 1 life.

When Noxan Zealot enters, create a tapped 5/5 black Demon enchantment creature token.
{T}, Pay 3 life: Target enchantment creature gains menace and deathtouch until end of turn. Activate only as a sorcery.

Defender
Phyten Bodyguards can attack as though it didn't have defender as long as you control three or more creatures.

Whenever Ram Wrangler attacks, until end of turn, gain control of target creature defending player controls with power less than or equal to the number of creatures in Ram Wrangler's pack. Tap it. It's attacking defending player. (Two or more creatures you control with equal power are in a pack.)

This spell costs {1} less to cast for each artifact and enchantment you control.
Reveal the top seven cards of your library. Put any number of noncreature, nonland cards from among them into your hand and the rest of the revealed cards into your graveyard.

Voracious 1 (As this enters, you may sacrifice an artifact or creature. If you do, it enters with a +1/+1 counter on it.)
Vigilance, reach