msem-instigator

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.

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.

Enchant creature (Target a creature as you cast this. This card enters attached to that creature.)
Enchanted creature can't attack or block.
At the beginning of your upkeep, you gain 1 life.

{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.

Haste
When Inciter of Spirits Scorned enters, return target creature card with mana value 3 or less from your graveyard to the battlefield. It gains haste. Sacrifice it at the beginning of the next end step.

{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.

When Infectious Corpse dies, each player loses 2 life.

Lifelink
Whenever Infectious Ego enters or attacks, exile the top card of target opponent's library. If it's a land card, that player gets a poison counter. You may play that card for as long as it remains exiled, and you may spend mana as though it were mana of any color to cast that spell.

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.

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.”

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

Each opponent plays with the top card of their library revealed.
During each of your turns, you may play one card from the top of an opponents' library, and you may spend mana as though it were mana of any color to cast that spell.

Once each turn, when a player casts a spell, you may choose two target players. Each of those players exiles cards from the top of their library until they exile a nonland card with mana value less than that spell's. They may cast those cards without paying their mana cost. Then they put the rest of the exiled cards on the bottom of their library in a random order. (The active player puts their spell on the stack first.)

Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.
{8}{G}, Exile Influence of Kruphix from your graveyard: Return up to two target cards from your graveyard to your hand.

[+1]: Look at the top two cards of your library. Put one of them into your hand and the other into your graveyard.
[–2]: Return target card from your graveyard to the battlefield face down.
[–6]: Turn any number of face-up nonland permanents of your choice face down.

When Ingredient Scroungers enters, if you control a creature with deathtouch, return target permanent card from your graveyard to your hand.

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.

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

As an additional cost to cast this spell, sacrifice a creature.
Enchant creature
Enchanted creature gets +4/+4, has flying, and is a Demon in addition to its other types.

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

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

Creatures you control get +2/+1 until end of turn.

Enchant creature
Whenever enchanted creature attacks, other creatures you control get +1/+2 until end of turn.

Scry 3, then reveal the top card of your library. Discard your hand, then draw cards equal to that card's mana value.