msem-instigator

When Aethermancer's Companion enters, aetherize up to two other non-Cat permanents you control. (Create tokens that are copies of each of them, then exile them.)
Recite {5}{W}{U} (You may cast this spell from your graveyard for its recite cost. If you do, exile it when it enters or if it would leave the battlefield.)

Return target creature to its owner's hand. Its controller loses 1 life.

Colossal 2—{6}{U} (You may cast this for its colossal cost to have it enter with two +1/+1 counters; or pay {6}{U} as a sorcery: Put two +1/+1 counters on it if it has none.)
When Titanic Fathomclaw's colossal ability puts one or more counters on it, return target instant or sorcery card from your graveyard to your hand.

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.)
Lifelink

As an instant or sorcery spell not cast from exile resolves, exile it instead of putting it anywhere else.
Once each turn, you may cast a card exiled with Eidetic Memory.

Flying, trample, haste
Whenever a land you control enters or a land is put into your graveyard from the battlefield, Skyscreecher Dragon deals 2 damage to each opponent.

You draw a card, lose 2 life, then create a Vial token. (It's an artifact with “{1}, Sacrifice this and another permanent: Draw a card. Activate only during your turn.”)

Equipped creature gets +1/+1 for each permanent attached to it.
Permanents attached to equipped creature have ward {3}.
Equip {1}

This spell costs {1} less to cast for each creature card in your graveyard.
Trample

Whenever Titanic Hardshell deals combat damage to a player, draw a card.
{2}{G}: Titanic Hardshell gains trample until end of turn.

Enchant creature
When Photon Barricade enters, draw a card.
Enchanted creature gets +1/+1 and can't attack.

At the beginning of your end step, any number of target players mill three cards.
{5}{U/B}, {T}: You may cast target instant or sorcery card from an opponent's graveyard without paying its mana cost. Activate only as a sorcery.

Gain control of target creature with power 4 or less until end of turn. Untap that creature. It gains haste until end of turn.

You may cast a spell with mana value X or less from your hand without paying its mana cost, where X is the number of lands you control.

Creatures you control get +1/+1.
{3}{W}{W}, Sacrifice To a Bright Future: Put a +1/+1 counter on each creature you control.

Permanents your opponents control enter tapped.
Whenever a permanent enters tapped and under your control, untap it.
Cycling {2} ({2}, Discard this card: Draw a card.)

This spell can't be countered.
Haste
Whenever a creature dealt damage by Ripper of the Fang Den this turn dies, put X +1/+1 counters on Ripper, where X is his power.

Equipped creature gets +1/+0 for each instant and sorcery card in your graveyard.
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Spare Supplies enters tapped.
When Spare Supplies enters, draw a card.
{2}, {T}, Sacrifice Spare Supplies: Draw a card.

Revive {3}{G} ({3}{G}, Exile this card from your graveyard: Create a token that's a copy of it except it has no mana cost. Revive only as a sorcery.)

Siphon (Each -1/-1 counter you put on your creatures up to their remaining toughness while casting this pays for {1}.)
Gain control of target nonland permanent.

You may exchange a creature you both own and control with a creature card in your hand that has the same mana value.
Flashback {1}{G} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

I, II — Put your choice of a flying or hexproof counter on target creature you control.
III — Creatures you control with counters on them can't be blocked this turn unless defending player pays {3} and spells that target those creatures cost an additional {3} to cast until your next turn.
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Nonenchantment spells cost {1} more to cast.
Whenever you cast an enchantment spell, you gain 1 life and draw a card.

({T}: Add {U} or {B}.)
Whenever Murmuring Falls becomes tapped, you lose 1 life unless you control two or more basic lands.