msem-instigator

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.

Choose target creature you control. Exile each creature you control. For each creature exiled this way, create a token that's a copy of the chosen creature, except it has haste and isn't legendary. At the beginning of the next end step, sacrifice those tokens, then return the exiled cards to the battlefield tapped.

Enchant creature
Whenever enchanted creature attacks, up to two target creatures can't block this turn. Up to one target creature blocks this turn if able.

Gestalt (When this or another creature enters under your control, you may merge it with the one in play, keeping counters and attachments. They become the permanent on top plus all abilities from under it.)
Whenever this creature attacks, target creature blocks it this combat if able.

This spell costs {1} less to cast for each tapped creature you control.
Whenever Incarnation of Enmity attacks, each other attacking creature gets +1/+0 until end of turn.

Incendiary Flow deals 3 damage to any target. If a creature dealt damage this way would die this turn, exile it instead.

When Incense Stoker enters, you may return target instant or sorcery card with mana value less than or equal to the number of differently named lands you control from your graveyard to your hand.

{R}, Tap two untapped artifacts you control: Incineration Expert deals 1 damage to any target.
{3}{R}, Tap eight untapped artifacts you control: Incineration Expert deals 8 damage to any target.

As a permanent you control explores an Aura, you may put it onto the battlefield attached to Inconspicuous Stowaway.
As long as Inconspicuous Stowaway is enchanted or equipped, she's a legendary 2/3 Cat Rogue named Agent C and has double strike.

Disgraced 1 (This enters with a -1/-1 counter. Whenever it deals combat damage to a player, remove all -1/-1 counters from it.)
Whenever Indebted Burglar becomes blocked, defending player loses 1 life.

Enchant creature
Enchanted creature gets +3/+2 and attacks each combat if able.

Create three 1/1 red Human creature tokens with haste. Sacrifice those tokens at the beginning of the next end step.
Draw a card.

This spell can't be countered.
Inescapable Blaze deals 6 damage to any target.

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

Menace
Ward—Pay 3 life.
When Infernal Direwolf enters, it fights up to one target creature an opponent controls. Excess damage Infernal Direwolf deals this way is dealt to that creature's controller instead.

Enchant creature
At the beginning of combat on your turn, create a token that's a copy of enchanted creature, except it has haste. Exile that token at the beginning of the next end step.

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.)

Whenever you cast an instant or sorcery spell, Infernal Immolator deals 2 damage to each opponent.

Enchant creature
Enchanted creature has “{R}, {T}: Create an X/1 red Elemental creature token with haste and trample, where X is this creature's power. Exile that token at the beginning of the next end step.”

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

Inferno Lash deals 2 damage to target creature or planeswalker. When it does, torment that permanent's controller. (They lose 3 life unless they discard a card or sacrifice a nonland permanent.)

Whenever a land you control enters, you may have target creature get +1/+0 and gain first strike until end of turn.

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.