msem-instigator

Flash
Enchant creature
When Ineffable Patronage enters, it deals 4 damage to up to one target attacking or blocking creature.
Enchanted creature gets +2/+2.

Target creature gets -1/-1 until end of turn.
Threshold — You may destroy that creature instead if seven or more cards are in your graveyard.

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.

Whenever Infernal Barrier is dealt damage, it deals 1 damage to each opponent.

Infernal Flames deals 3 damage to target player or planeswalker.
Tether (Then if you cast this from your hand, you may exile it tethered to a creature you control. When it dies, you may cast this from exile without paying its mana cost.)

Enchant creature
Enchanted creature gets +3/+0 and has trample.
Madness {1}{R} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Haste
When Inferno Forerunner enters, you may have target creature gain haste until end of turn.

Create two 1/1 green Insect creature tokens, then put a +1/+1 counter on target creature you control for each Insect you control.

Whenever Infiltrator of the Anomalous deals combat damage to a player, add {R}. Until end of turn, you don't lose this mana as steps and phases end.

Enchant creature (Target a creature as you cast this. This card enters attached to that creature.)
Enchanted creature can't be blocked.
{1}{U}: Enchanted creature gains hexproof until end of turn.

When Influential Wildborn enters, proliferate. (Choose any number of permanents and/or players with counters on them, then give each another counter of each kind already there.)
Persist (When this creature dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)

Counter target spell unless its controller pays {4}. Create an Idol token. (It's an artifact with “{1}, Sacrifice this artifact: Put a +1/+1 counter on target creature. Activate only as a sorcery.”)

Whenever you cast a spell, untap Inglorious Blaze.
{T}: Inglorious Blaze deals 1 damage to target player or planeswalker.

{T}: Add one mana of any color.
Whenever you tap Ingrained Virago for mana, each opponent loses 1 life.

Enchant creature
When Inherited Blessing enters, remove all -1/-1 counters from each creature you control.
Enchanted creature gets +2/+2 and has first strike.

Flying
Attain {4}{B} ({4}{B}: Transform this. Spend at least three colors of mana to activate this, and only as a sorcery.)

Create a 3/3 white Construct enchantment creature token.

Put two +1/+1 counters on target creature. (Cast a copy of this spell once while this creature is on the battlefield.)

Sleight (You may cast this spell as though it had flash if you pay {1} more to cast it.)
Enchant creature you don't control
Embody (Enchanted creature is a copy of this card except for its types.)

Injustice deals 4 damage to target creature. Post a bounty on up to one other target creature. (Put a bounty counter on that creature. It has “When this creature dies, each opponent draws a card” as long as it has a bounty counter on it.)

When Ink Seer dies, you draw a card, lose 1 life, and create a Treasure token.

Enchant creature
Enchanted creature gets +2/+0 and has trample.