msem-instigator

This spell can't be countered.
Flying, menace, haste
Ward—Sacrifice a creature. (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player sacrifices a creature.)

Other creatures you control get +2/+0 and have menace.
Whenever another creature you control dies, if it wasn't sacrificed, sacrifice a creature.

Target creature you control gains hexproof and indestructible until end of turn. If it's a Knight or Soldier, put a +1/+1 counter on it.

Trample
Lian Taizi gets +1/+1 for each card in your hand.
When Lian Taizi enters, return any number of target cards with different mana values from your graveyard to your hand.

[+2]: Up to one target creature gets -1/-1 until your next turn. Tap it. You may remove all counters from it.
[–2]: Destroy target creature with no counters on it.
[–10]: Each opponent's life total becomes equal to the number of creatures they control.

Converge — Exile up to X nonland permanents you control, where X is the number of colors of mana spent to cast Reenter Orbit, then return them to the battlefield under your control.

Mill a card. Target creature gets -X/-X until end of turn, where X is the number of cards put into your graveyard from anywhere this turn.

{1}{U}, {T}, Discard a card: Reveal the top card of your library. Counter target spell unless its controller pays {X}, where X is the mana value of that card.

Spirited (When this enters, you may activate one of its activated abilities without paying its cost.)
{1}, {T}, Discard a card: You gain 4 life.
{2}, {T}, Pay 2 life: Create a 1/1 colorless Construct artifact creature token. It can't block this turn.
{3}, {T}, Sacrifice a permanent: Draw a card.

When Consumption Catalyst enters, create a Vial token. (It's an artifact with “{1}, Sacrifice this and another permanent: Draw a card. Activate only during your turn.”)
Whenever you draw a card, each opponent loses 1 life and you gain 1 life.

Blooming Needles enters tapped unless you control another Desert.
{T}: Add {R} or {G}.

Concord — When Dolphin Rider enters, if there are four or more card types among permanents you control, you gain 5 life.

{X}{G}: Put X +1/+1 counters on target noncreature, nonplaneswalker permanent you control. It becomes an Elemental creature with base power and toughness 0/0 in addition to its other types. (This effect lasts indefinitely.)

Whenever you make first contact, Oscuran Wingmate gains flying until end of turn. (You make first contact the first time each turn you cast a spell with a name not in your graveyard or control already.)

Equipped creature gets +1/+1 and has lifelink.
Whenever equipped creature dies, if it wasn't a token, you may pay {3}. If you do, create a token that's a copy of that creature and attach Bloodguard's Hand to it.
Equip {3}

When Mindbreak Artisan enters, you may search your library for an artifact card, reveal it, shuffle, then put that card on top.
Other artifacts you control have “You may choose not to untap this artifact during your untap step” and “{3}{U}{U}, {T}: Gain control of target creature for as long as you control this artifact and it remains tapped.”

Vigilance
When Envoy of Karametra enters, for each kind of counter on target permanent, put another counter of that kind on it or remove one from it.

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

Whenever Fleshwarper or another Horror you control dies, each opponent loses 1 life and you gain 1 life. You may mill a card.

{2}{U}{B}: Return Depth Charger to its owner's hand. If you do, return target creature to its owner's hand. That player discards a card.

Desecrate (When this creature enters, you may sacrifice an artifact or land.)
When Back-Alley Vandal desecrates a permanent, put a +1/+1 counter on Back-Alley Vandal.

Torrent of Ankuliths deals 5 damage to target creature. Create a 1/1 red Elemental creature token.

Flash
When Pyramid Lord enters, copy target instant or sorcery spell. You may choose new targets for the copy.
Mirage {1}{R}{R} (You may cast this spell for its mirage cost. If you do, sacrifice it at the beginning of the next cleanup step.)

Gain control of target creature until end of turn. Untap that creature. It gains haste until end of turn.
Agonize (You may cast this card from your graveyard by putting a -1/-1 counter on a creature you control in addition to paying its other costs. Then exile this card.)