msem-instigator

Once each turn, when you gain life, you may exile the top card of your library. You may play that card this turn.
Whenever you cast your second spell each turn, Ignition Engine deals 2 damage to target player or planeswalker.

Ignition Point deals 3 damage to any target.
The next card you cast this turn can be cast as though it has flash.

Flash
Whenever Iken Company Nightwalker deals combat damage to a player, put a +1/+1 counter on it.

Sabotage — Whenever an opponent or permanent an opponent controls becomes the target of a spell you control, Iken Troubleshooter deals 2 damage to each opponent.

Whenever you tap an artifact or land for mana, add one mana of any type that permanent produced.

Shuffle any number of cards from your graveyard into your library.
Scry 1, then draw a card.

Imitator of Drakes has flying as long as it has a +1/+1 counter on it.
{2}{U}: Put a +1/+1 counter on Imitator of Drakes.

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.

Draw two cards, then you may put a land card from your hand onto the battlefield. If you cast In Dire Straits during your turn for its reconstruct cost, create X 3/2 green Horror creature tokens, where X is the number of lands you control.
Reconstruct {8}{G}{G}{U}{U} (You may cast this from your graveyard for its reconstruct cost reduced by the mana value of a permanent you sacrifice as you cast it this way. Then exile this.)

This spell costs {2} less to cast if there's a storied card in your graveyard. (Enchantments and legendary cards are storied.)
Search your library for a storied card, reveal it, put it into your hand, then shuffle.

{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.

This spell costs {1} less to cast for each creature and/or planeswalker card in your graveyard.
Return target creature or planeswalker card from your graveyard to the battlefield.

{W}{B}, Shuffle Inexorable Explorer into your library: Return target creature card from your graveyard to the battlefield.
{W}{B}, Sacrifice a creature: Return Inexorable Explorer from your graveyard to the battlefield tapped.

Inquirer, Roaming Rover attacks each combat if able.
Whenever Inquirer deals damage to an opponent, draw a card.

Whenever Inquisitive Guardian deals combat damage to an opponent, you may exile a nonland card from your graveyard. If you do, draw a card.
{U}: Inquisitive Guardian gains flying until end of turn.

Whenever Insatiable Abomination or another Horror enters the battlefield under your control, each player mills four cards.
Exile a creature card from your graveyard: Tap target Horror you control. It gains indestructible until end of turn.

Whenever you cast or copy an instant or sorcery spell this turn, Instant of Brilliance deals 1 damage to each opponent.
Copy target instant or sorcery spell you control. You may choose new targets for the copy.

Whenever a creature enters the battlefield, it deals damage equal to its power to any target of its controller's choice.
When Interplanar Raid enters the battlefield, you may aetherize target creature you control. (To aetherize, create a token that's a copy of it, then exile that token.)

{T}: Add {C}.
{1}, {T}: Add two mana of different colors. Activate only if you control five or more lands.

Put a +1/+1 counter on target creature. It gains indestructible until end of turn.

Flash
Deathtouch, lifelink
Whenever Irika, Wielder of Secrets deals combat damage to a player, you may pay {U/B}. If you do, you draw a card and you lose 1 life.

Trample
Augmented — Whenever you cast a spell, if you've spent {W}{U}{B}{R}{G} to cast spells this turn, put a +1/+1 counter on Isolated Guardian. It loses this ability and gains “Whenever this attacks, put two +1/+1 counters on each of up to two target creatures.”

Eureka! (At the beginning of each end step, you get a research counter if you cast a spell this turn. Then if you have eight or more research counters, remove them and create a Masterpiece token of your choice.)
Whenever you cast a noncreature spell, create a 1/1 colorless Construct artifact creature token.

[+2]: You may draw a card. If you don't, create a Treasure token. Repeat this process once.
[0]: Iviana deals X damage to each creature you don't control, where X is 2 plus twice the number of Dragons you control.
[–3]: Create a 5/5 red Dragon creature token with flying and haste.