msem-instigator

Choose a color or card type. Target permanent gains protection from the chosen color or type until end of turn.
Inscribe {3}{W}{U} ({3}{W}{U}: Exile this card from your hand inscribed on a creature you control. Whenever that creature attacks, its controller may cast a copy of the inscribed card without paying its mana cost. Inscribe only as a sorcery.)

Flying
Saki of the Sea and Sky gets +1/+1 for each card inscribed onto it and each permanent attached to it.

Target player mills seven cards.
Inscribe {3}{U}{B} ({3}{U}{B}: Exile this card from your hand inscribed on a creature you control. Whenever that creature attacks, its controller may cast a copy of the inscribed card without paying its mana cost. Inscribe only as a sorcery.)

Creatures you control lose poisonous and can't have or gain poisonous.
Snakes you control deal damage to players in the form of poison counters.

At the beginning of each opponent's draw step, that player draws an additional card, then discards a card.
Whenever an opponent discards a card, you draw a card and you gain 1 life.

At the beginning of your end step, if an opponent lost life this turn, Kogane the Crimson Consort deals 2 damage to each opponent and you gain 2 life.

At the beginning of each player's upkeep, that player may sacrifice a creature. If they don't, they discard a card.

{T}, Sacrifice a land: Destroy target land.

Whenever Imako, Ninefingers becomes tapped, exile the top three cards of target opponent's library face down.
You may look at cards exiled with Imako.
Sacrifice Imako: Turn all cards exiled with it face up. Exile all cards with those names from your opponent's graveyards.

Creatures with defender you control can attack as though they didn't have defender.
Each creature you control assigns combat damage equal to its toughness rather than its power.

If a source you control would deal exactly 1 damage to a permanent or player, it deals 3 damage instead.

Equipped creature gets +2/+2.
Whenever equipped creature attacks, creature spells you cast cost {2} less to cast this turn.
Equip {2}

Whenever Student of the Coil attacks, target creature gains poisonous 1 until end of turn. (Whenever that creature deals combat damage to a player, that player gets a poison counter.)

When Spectral Kitsune enters, you may remove a counter from target player or permanent.

Colorless creatures you control have “{T}: Add {C}.”

Target creature gains deathtouch and poisonous 1 until end of turn. (Whenever that creature deals combat damage to a player, that player gets a poison counter.)
Inscribe {1}{G} ({1}{G}: Exile this card from your hand inscribed on a creature you control. Whenever that creature attacks, its controller may cast a copy of the inscribed card without paying its mana cost. Inscribe only as a sorcery.)

Flash

Poisonous 2 (Whenever this creature deals combat damage to a player, that player gets two poison counters.)
Snakes you control can't be blocked by creatures with power 2 or less.

Target creature gets +1/+1 until end of turn. When that creature dies this turn, create a 2/2 colorless Spirit creature token.
Inscribe {3}{G} ({3}{G}: Exile this card from your hand inscribed on a creature you control. Whenever that creature attacks, its controller may cast a copy of the inscribed card without paying its mana cost. Inscribe only as a sorcery.)

At the beginning of your upkeep, you may put a reinforcement counter on Moranai Paragon.
Whenever Moranai Paragon attacks, you may put a creature card with mana value equal to the number of reinforcement counters on Moranai Paragon from your hand onto the battlefield.

Other creatures you control get +0/+1.

Exile target artifact or enchantment. Its controller may search their library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Until end of turn, creatures you control get +1/+1 and gain trample and poisonous 1. (Whenever one of those creatures deals combat damage to a player, that player gets a poison counter.)

Art of war — At the beginning of your end step, if Kuryu Swordsman dealt damage to an opponent this turn, you may have Kuryu Swordsman fight target creature you don't control. (Each deals damage equal to its power to the other.)