msem-instigator

Flying, haste
Whenever Phoenix of Agonas attacks, you may discard a card. If you do, draw a card.
{4}{R}: Return Phoenix of Agonas from your graveyard to your hand. This ability costs {X} less to activate, where X is your devotion to red. (Each {R} in the mana costs of permanents you control counts toward your devotion to red.)

When Adept of Rations enters, create a Vial token. (It's an artifact with “{1}, Sacrifice this and another permanent: Draw a card. Activate only during your turn.”)
Tokens you control have “{2}, {T}, Sacrifice this token: You gain 3 life.”

Flying
Spelldust Sprite gets +1/+1 as long as you control four or more creatures with flying.
If you would create a token, you may instead create a token that's a copy of Spelldust Sprite, except it doesn't have this ability.

Protection from instants and from sorceries
When Warbringer Titan enters or attacks, create two 1/1 white Soldier creature tokens with melee. (Whenever that creature attacks, it gets +1/+1 until end of turn for each opponent you attacked this combat.)

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.”)

You may play an additional land on each of your turns.
{4}{U}{U}: Transform Misthollow Rites. Activate only as a sorcery.

Trample
When Wasteland Ravagers enters, you may sacrifice a land or exile a land card from your graveyard. If you do, creatures you control get +1/+0 and gain haste until end of turn.

Vigilance
Creatures you control with a +1/+1 counter on them have mentor. (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.)
Creatures you control with no +1/+1 counters on them have training. (Whenever this creature attacks with another creature with greater power, put a +1/+1 counter on this creature.)

Experience (Whenever this creature attacks, if it has fewer than three +1/+1 counters on it, put a +1/+1 counter on it.)
Whenever a +1/+1 counter is put on Flamerider, you may have it deal damage equal to its power to target creature.

Defender (This creature can't attack.)
{W}, {T}: You gain 1 life.

Experience (Whenever this creature attacks, if it has fewer than three +1/+1 counters on it, put a +1/+1 counter on it.)
When Determined Koi has three or more +1/+1 counters on it, remove them all and transform it.

Haste
When Gilded Gearhulk enters, you may destroy target noncreature, nonland permanent.

Frenzy 1 (Whenever this creature attacks and isn't blocked, it gets +1/+0 until end of turn.)

Menace
Whenever Silver-Dawn Radiant becomes the target of a spell or ability you don't control, it deals damage equal to its power to that spell or ability's controller.

Trample, haste
When Weak-Spot Colossus is dealt exactly 1 damage, destroy it.

When AOSE Extractor enters, crystallize. (Put a +1/+1 counter on a creature you control or create a Treasure.)

Archive 2 (As this enters, shuffle the top two cards of your main library into a new face up library. Sacrifice this after the archived library is empty.)
{R}{W}: Put a nontoken artifact or creature you own on the bottom of the archived library. Create a token that's a copy of it.

At the beginning of combat on your turn, you may exert an untapped creature you control with power 4 or greater. If you do, attach Giant's Blade to that creature. (An exerted creature won't untap during your next untap step.)
Equipped creature attacks each combat if able.
Equipped creature gets +2/+0 and has haste.
Equip {3}

You may have Better Half enter as a copy of any creature on the battlefield, except it's a Reflection in addition to its other creature types and it has distorted. (It can be blocked by tapped creatures but not untapped creatures.)

Death knell — Return an Aura card with mana value 5 or less from your graveyard to the battlefield. (As a creature you control dies, trigger one death knell of that creature or another permanent you control.)
As long as Inconspicuous Otter is enchanted or equipped, he's a 3/4 legendary Otter Rogue named Agent O and has menace.

At the beginning of your upkeep, put a charge counter on Hexstone.
{T}, Sacrifice Hexstone: Choose a nonland permanent type. Destroy each permanent of the chosen type with mana value less than or equal to the number of charge counters on Hexstone.

[+1]: Whenever a creature you control attacks this turn, Aleryn, Dungeon Disabler deals 1 damage to the defending player.
[–1]: Add X mana in any combination of {R} and/or {G}, where X is the number of creatures you control.
[–6]: You get an emblem with “Whenever a player casts a spell, this emblem deals 3 damage to any target.”

Target creature gets +1/+0 until end of turn. Add {R}.

Target creature gets +2/+2 for each creature blocking it and gains trample until end of turn.
Fuse (You may cast one or both halves of this card from your hand.)

Enchant creature
Enchanted creature gets +1/+0 for each card type among cards in your graveyard and has menace.
Fleeting {B} (You may cast this spell for its fleeting cost. If you do, sacrifice it at the beginning of the next end step.)