msem-instigator

Whenever another creature you control enters, target instant or sorcery card in your graveyard with mana value less than or equal to that creature's power gains flashback until end of turn. The flashback cost is equal to its mana cost. (You may cast that card from your graveyard for its flashback cost. Then exile it.)

Whenever one or more creatures you control deal combat damage to a player or planeswalker, create a Clue token.
{G}{U}, Sacrifice a Clue: Put a +1/+1 counter on target creature. Proliferate.

Put a +1/+1 counter on target creature you control. Untap that creature.

The next creature spell you cast this turn can be cast as though it had flash. When that creature enters this turn, it gains lifelink until end of turn.

Exile up to three instant or sorcery cards from your graveyard. You may cast a copy of each card exiled this way without paying its mana cost.

At the beginning of combat on your turn, creatures you control gain your choice of trample, menace, haste, or +1/+0 until end of turn.

{1}{R}, {T}, Sacrifice an artifact: Elise, Maktali Prodigy deals 2 damage to any target.
{1}{U}, {T}, Sacrifice an artifact: Return target nonland permanent to its owner's hand.
{3}{U}{R}, {T}, Sacrifice three artifacts: Discard your hand, then draw seven cards.

Flash
Prowess
When Ella enters, create two 1/1 blue Wizard creature tokens with prowess.
Whenever you cast a noncreature spell, you may sacrifice a creature. If you do, copy that spell. You may choose new targets for the copy.

At the beginning of your upkeep, you may search your library for a permanent card with mana value 1 or less, put it onto the battlefield, then shuffle.

Whenever you cast an instant or sorcery spell, exile cards from the top of your library until you exile an instant or sorcery card. You may cast that card until you exile another card with this ability.

When Ema, the Traveler enters, reveal the top five cards of your library. Put any number of legendary cards revealed this way into your hand and the rest on the bottom of your library in any order.
{2}{B}: Another target legendary permanent gains indestructible until end of turn.

Defender, reach
{T}, Discard a card: Create a 0/2 red and green Scarecrow creature token with defender and reach.
{R}{G}, {T}: Embergourd Scarecrow deals X damage to target player or planeswalker, where X is the number of creatures with defender you control.

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.)
When this creature dies, it deals X damage to target player or planeswalker, where X is the number of cards and tokens merged with it.

When Embrace Samang enters, put a charge counter on it for each color among permanents you control.
At the beginning of your first main phase, remove a charge counter from Embrace Samang. If you do, draw a card, then add one mana of any color.

When Embrace the Veil enters, you may exile target nonland permanent you don't control until Embrace the Veil leaves the battlefield.
Whenever you cast a spell with mana value 5 or greater, you may put a card exiled with Embrace the Veil into its owner's graveyard and return Embrace the Veil to its owner's hand.

Trample
Assault {2}{R}{G} (Whenever this attacks, if it has no +1/+1 counters on it, you may pay its assault cost to put a +1/+1 counter on it.)
If one or more +1/+1 counters would be put on a creature you control, that many plus one +1/+1 counters are put on it instead.

When Emerging Ankulim enters, return each non-Elemental creature to its owner's hand, then Emerging Ankulim deals damage to each player equal to the number of cards in that player's hand.

Artifact creatures you control can't be blocked by nonartifact creatures.
{2}{U}{R}: Put a +1/+1 counter on an artifact creature you control or a progress counter on a Project you control.

Put a +1/+1 counter on each of up to two target creatures you control.
Draw a card.

Inspired — Whenever Emperor Dan Te Mogui becomes untapped, look at the top three cards of your library. Put one into your graveyard, one on the bottom of your library, and one on top.
When Emperor Dan Te Mogui dies, you may put it on the bottom of your library. If you do, return target permanent card from your graveyard to your hand.

[+1]: Emperor Tzhai deals 1 damage to each creature, planeswalker, and opponent you don't control.
[0]: Target creature can't attack you or Emperor Tzhai until Emperor Tzhai leaves the battlefield.
[–10]: You control target player.

When Empire's Glory enters, draw a card, then choose a card name.
Whenever a creature with the chosen name you control enters, put a +1/+1 counter on each creature you control that shares a creature type with it. Those creatures gain haste until end of turn.

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.)

Whenever you cast a spell, draw X cards, where X is Enai, Who Wanders Alone's power.
As long as there are no other untapped creatures on the battlefield, Enai's power and toughness are switched.

Archive 5 (As this enters, shuffle the top five cards of your main library into a new face up library. Sacrifice this after the archived library is empty.)
Encylopetia's power and toughness are each equal to the number of cards in the archived library.
At the beginning of your upkeep, exile a card from the archived library at random. You may play it this turn.