msem-instigator

Enchant creature
Enchanted creature gets +2/+0 and has first strike.
Mirage {R} (You may cast this spell as though it had flash for its mirage cost. If you do, sacrifice it at the beginning of the next cleanup step.)

Distribute three +1/+1 counters among any number of creatures you control.
Metamorph {1}{G} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up and cast it at any time for its metamorph cost.)

Destroy target artifact.
Reprise {R} (As you cast an instant or sorcery spell, you may exile one card with reprise from your graveyard and pay its reprise cost. If you do, add its effects to that spell.)

Enchant creature
Enchanted creature gets +2/+2 and has trample and indestructible.

Whenever a face-down creature you control attacks, defending player loses 1 life.
{2}, Discard a card: Manifest the bottom card of your library. Activate only once each turn. (To manifest a card, put it onto the battlefield face down as a 2/2 creature. Turn it face up any time for its mana cost if it's a creature card.)

As an additional cost to cast this spell, discard a nonland card.
All creatures get -X/-X until end of turn, where X is the discarded card's mana value.

First strike
Art of war — At the beginning of your end step, if Imperial Kensai dealt damage to an opponent this turn, you may pay 1 life. If you do, put a +1/+1 counter on Imperial Kensai.

Imperial Marketplace enters with a charge counter on it.
{T}: Add {C}.
{T}, Remove a charge counter from Imperial Marketplace: Put a +1/+1 counter on target creature you control.

At the beginning of each upkeep you may pay {W}. If you do, tap target creature.

Enchant land you don't control
Whenever enchanted land becomes tapped, you may draw a card.

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)

Enchant creature
Enchanted creature can block any number of creatures each combat.

Defender

Motivate 2 (When this creature enters, you may motivate target creature with less power than this by putting two +1/+1 counters on it.)

Ferocious — At the beginning of each combat, if you control a creature with power 4 or greater, Impressible Cub gets +1/+1 until end of turn.

Exile the top card of your library. Impulsive Action deals damage to any target equal to that card's mana value plus one. Until end of turn, you may play that card.

Enchant creature
Whenever enchanted creature deals combat damage to a player, exile the top card of your library. Until end of turn, you may play that card.

Trial 4 (As you cast this spell, an opponent of your choice may pay 4 life. If they don't, they fail the trial.)
Search your library for an Angel card, reveal it, put it into your hand, then shuffle. If the trial was failed, non-Angel, non-God creatures can't attack or block until your next turn.

Equipped creature gets +3/+2 and must be blocked by a creature that doesn't share a color with it if able.
Equip {4}

When Inexperienced Martyr dies, each opponent loses 1 life.

Enchant creature (Target a creature as you cast this. This card enters attached to that creature.)
Enchanted creature gets -1/-1.
Whenever enchanted creature attacks, its controller loses 2 life.

Deathtouch
Whenever Infected Null attacks, each player loses 1 life.

When Infectious Corpse dies, each player loses 2 life.

At the beginning of each end step, if a player lost 5 or more life this turn, create a 5/5 black Demon creature token with flying.

Whenever a creature you control enters, you may have target creature get +1/+1 and gain flying until end of turn.