msem-instigator

Vigilance
Whenever another creature you control enters, scry 1.
{T}: Reveal the top card of your library. If it's a creature card, put it into your hand. Otherwise, you may put it into your graveyard.

Reach
When Primordial Artisan enters or attacks, look at the top card of your library. If it's a permanent card with mana value less than or equal to your devotion to green, you may put it onto the battlefield. (Each {G} in the mana costs of permanents you control counts toward your devotion to green.)

Pristine Delta enters tapped.
{T}: Add {W} or {U}.
{2}{W}{U}, {T}, Sacrifice Pristine Delta: Draw a card.

Flying
Whenever you scry, create a 1/1 blue Chimera creature token with flying. This ability triggers only once each turn.

Scry 1. Draw a card. Scry 1.

Enchant creature
When Prophet's Paranoia enters, tap enchanted creature, then scry 2.
Enchanted creature loses all abilities and doesn't untap during its controller's untap step.

When Propulsion Pack enters, create a 1/1 colorless Servo artifact creature token and attach Propulsion Pack to it.
Equipped creature gets +1/+1 and has flying.
Equip {3}{U}

As Protean Jar enters, choose a creature type.
Each creature you control of the chosen type enters with an additional +1/+1 counter on it.
{2}: If Protean Jar isn't a creature, it becomes a copy of target creature you control of the chosen type, except it has Protean Jar's other abilities. Activate only as a sorcery.

Counter target spell unless its controller pays {2}.
Put a +1/+1 counter on a creature you control.

Flash
When Purehorn Rescuer enters, return target permanent card with mana value X or less from your graveyard to the battlefield, where X is your devotion to white. (Each {W} in the mana costs of permanents you control counts toward your devotion to white.)

Enchant creature you control
When Purphoros's Benefaction enters, scry 2.
Enchanted creature gets +1/+1 and has haste.

Chronicle (As this enters and after your draw step, add a lore counter. Stop after III.)
[Lore I-II] Purphoros's Gemback deals 1 damage to target player or planeswalker.
[Lore III] Create a Treasure token. (It's an artifact with “{T}, Sacrifice this artifact: Add one mana of any color.”)

Indestructible
As long as your devotion to red is less than five, Purphoros isn't a creature.
Whenever you attack, Purphoros deals 1 damage to any target.
{3}{R}: Discard up to two cards, then draw that many cards.

Flying
When Pyromanticore enters, it deals X damage to target creature or planeswalker an opponent controls, where X is your devotion to red. Excess damage is dealt to that permanent's controller instead. (Each {R} in the mana costs of permanents you control counts toward your devotion to red.)

{T}: Add {C}.
{1}, {T}: Add one mana of any color. This ability costs {1} less to activate if there are three or more colors among cards in your graveyard.

Rhapsody {4}{R}{R} (Pay {4}{R}{R} to cast this as a 4/4, or as a sorcery to make it become a 4/4.)
When Reckless Guardian dies, create X 1/1 colorless Servo artifact creature tokens, where X is Reckless Guardian's power.

Exile the top two cards of your library. Until the end of your next turn, you may play those cards.

When Reconnaissance Expert enters, mill four cards.
When Reconnaissance Expert dies, return target noncreature permanent card from your graveyard to your hand.

Counter target spell.
{1}{U}, Exile Refute from your graveyard: Draw a card.

Flying, lifelink, haste
{W}{U}{B}{R}{G}, Exile Remi Amber, Slyten Specialist: Return Remi Amber to the battlefield transformed at the beginning of your next main phase.

[+1]: Create a 1/1 blue Elemental creature token with flying, then crystallize twice. (Put a +1/+1 counter on a creature you control or create a Treasure.)
[–3]: Exile target nonland permanent. As long as it's exiled, its owner may pay {W}{U}{B}{R}{G} as a sorcery to put it into their hand.
[–7]: You get an emblem with “Pay 1 life: Add one mana of any color.” Then you gain 100 life.

When Repurposed Custodian enters, shuffle any number of target cards from graveyards into their owner's libraries.

As long as there are three or more creature cards in your graveyard, Returned Minotaur gets +1/+1 and has menace.

Ward {2}
When Rewriter of Flesh enters, target creature you control becomes an enchantment and loses all other card types. (It still has its abilities, but it's no longer a creature.)

Enchant creature you control
When Rise of Heroes enters or enchanted creature dies, search your library for a creature or planeswalker card with mana value 3 or less, reveal it, put it into your hand, then shuffle.
Enchanted creature gets +1/+1 for each creature and/or planeswalker you control.