msem-instigator

During each of your turns, you may cast a card with a cycling ability from your graveyard by discarding a card in addition to paying its other costs. If that spell would be put into your graveyard, exile it instead.
Cycling {2} ({2}, Discard this card: Draw a card.)

Starting with you, each player either passes or reveals the top card of their library. Each player that revealed a card this way pays life equal to its mana value. If a player can't, that player passes. Then each player who hasn't passed yet puts that card into their hand. Repeat this process until each player has passed.

{T}: Add {B} or {G}. You lose 1 life unless you have less life than an opponent.

Enchant creature
Enchanted creature gets +2/+2 and has flying and haste.
When enchanted creature dies, return it to the battlefield under its owner's control.

CySec Nexus enters tapped.
{T}: Add {W} or {U}.
{W}{U}, {T}: Create a Function token with “Flash.” Activate only as a sorcery. (It's an enchantment. As you cast an instant or sorcery spell, sacrifice any number of Functions to add their effects to that spell.)

Ashela, the Russet Grove enters tapped.
{T}: Add {C}.
{T}, Pay 1 life: Add {R}, {G} or {W}.
{3}, {T}: Return Ashela to its owner's hand.

Wildfire Elemental has frenzy 4 as long as you control no other creatures. (Whenever this creature attacks and isn't blocked, it gets +4/+0 until end of turn.)
Wildfire Elemental has frenzy 4 as long as you have no cards in hand.

Tortle Traveler enters tapped.
When Tortle Traveler enters, it explores. (Reveal the top card of your library. Put that card into your hand if it's a land. Otherwise, put a +1/+1 counter on this creature, then put the card back or put it into your graveyard.)

Destroy target artifact or enchantment. If that permanent was a token, proliferate. (Choose any number of permanents and/or players with counters on them, then give each another counter of each kind already there.)

Enchant creature
When Sting of the Manticore enters, scry 2.
Enchanted creature gets +1/+0 and has deathtouch.

First strike
Art of war — At the beginning of your end step, if Imperial Kensai dealt damage to an opponent this turn, you may pay 1 life. If you do, put a +1/+1 counter on Imperial Kensai.

Unstoppable Slaughter deals 1 damage to each creature and each player. Whenever a creature dealt damage by Unstoppable Slaughter this turn dies this turn, repeat that process.

Defender
When Immured Fiend enters, target opponent discards two cards.

(As an Encounter enters, choose an opponent to protect it. You and others can attack it. When defense counters are removed, create a 0/0 Army token if you don't control one, then put that many +1/+1 counters on a Army you control.)
When Soli Rising enters, reveal cards from the top of your library until you reveal a creature card. Put that card into your hand and the rest on the bottom of your library in a random order.

Trample
You may cast Sandswim Titan from exile. If you do, it enters with three +1/+1 counters on it.

You draw two cards and you lose 2 life. Each opponent draws a card.

Frenzy 2 (Whenever this creature attacks and isn't blocked, it gets +2/+0 until end of turn.)
Whenever Airam, Packleader becomes blocked, other creatures you control get +1/+1 until end of turn.

Eradicating Flames deals X damage to each creature and each player. If X is 5 or more, Eradicating Flames can't be countered and the damage can't be prevented.

Create a tapped Plains token, Island token, Swamp token, Mountain token, or Forest token.
Compose (Then if you cast this from your hand, exile it and create a Saga token with “r3—You may cast a copy of this card from exile without paying its mana cost.”)

When Exiled Necromancer enters, return target permanent card with mana value 1 or less from your graveyard to the battlefield.

Deathtouch, protection from legendary
Vielle, Undercity Wayfarer has all loyalty abilities of permanents on the battlefield that cost +1, +0, or -1. (Before cost changes. Add or remove loyalty counters from Vielle to pay their loyalty costs.)

As Sunflower Fields enters, you may pay 3 life. If you don't, it enters tapped.
{T}: Add {R}, {G}, or {W}.

First strike, menace, lifelink
{X}{2}{B}, Discard Wihtfyr: Create a tapped 0/0 Skeleton Army creature token with “This creature gets +1/+1 for each creature card in your graveyard.” For each of up to X Armies, put your choice of a first strike, lifelink, or menace counter on that Army.

Whenever Study Sphere or another artifact or enchantment you control enters, rouse 1. (Put a +1/+1 counter on a permanent you control. If it isn't a creature, tap it and it becomes a 0/0 creature in addition to its other types.)

Creatures you control get +1/+0 for each color among permanents you control and have haste.
Whenever you cast a white, blue, black, or green instant or sorcery spell, copy it for each of its colors. You may choose new targets for the copies.