msem-instigator

Sacrifice two other creatures: Monstrosity 2. (If this creature isn't monstrous, put two +1/+1 counters on it and it becomes monstrous.)
When Flailing Terror becomes monstrous, target opponent sacrifices two creatures.

Whenever equipped creature attacks, it gets +1/+0 until end of turn for each other attacking creature.
Tap two untapped creatures you control: Equipped creature gains trample until end of turn.
Equip {3}

Oshiruko Whisperwalker can't be blocked except by Rogues.
Whenever a creature is returned to its owner's hand, you may draw a card. If you do, discard a card.

Flying (This creature can't be blocked except by creatures with flying or reach.)
Whenever Lord Jared, the Griffin Knight attacks, put a +1/+1 counter on each other attacking creature you control.

{T}: Add {C}.
Sacrifice a nonland permanent: Ayala's Effigy becomes a 2/2 Construct artifact creature until end of turn.

Return target creature or land card from your graveyard to your hand. You may shuffle up to three cards from your graveyard into your library.

Menace, haste
Other Centaurs you control get +1/+0.

Seaside Skimmer can't be blocked if you've cast a Dragon spell or Adventure spell this turn.

Flying
When Cloudheath Sentinel enters, return target artifact card with mana value 2 or less from your graveyard to the battlefield.

Hexproof from enchantments (This creature can't be the target of enchantment spells or abilities your opponents control.)

Encourage ({T}: Another target creature you control gets +1/+1 until end of turn. Encourage only as a sorcery.)
{T}: Add {G}.
Whenever Hierarch Ranger encourages a creature, add one mana of any color.

Create two 2/2 white Griffin creature tokens with flying. If you control a legendary creature, create three of those tokens instead.

Noncreature spells your opponents cast cost {1} more to cast.

Pressure—{2}{U}{U}, Discard your hand. (You may cast this spell for its pressure cost if seven or more cards are in your graveyard.)
Reveal the top seven cards of your library. Put any number of noncreature, nonland cards from among them into your hand and the rest into your graveyard.

Wanderlust — When Ardent Explorers enters, if you control four or more differently named lands, create a 1/1 Scout creature token that's all colors. That token gains haste until end of turn.

{W}: Parish Custodian gains lifelink until end of turn. (Damage dealt by this creature also causes you to gain that much life.)

Tithe (As you cast this spell, you may tap three artifacts and/or creatures you control.)
Creatures can't attack this turn. If this spell's tithe was paid, opponents can't cast spells this turn.

Flying
Spirited (When this creature enters, you may activate one of its activated abilities without paying its cost.)
{3}{R}{R}, {T}: Exile an instant card with mana value 3 or less from your graveyard, then cast a copy of a card exiled with Thunderlash Mystic without paying its mana cost.

Lifelink
Whenever one or more other creatures with power 2 or less you control enter, you gain 1 life. If your life total is greater than your starting life total, draw a card instead. This ability triggers only once each turn.

Cadence (Whenever you cast a spell, if its mana value is greater than this creature's power, put a +1/+1 counter on this creature.)

This spell can't be countered.
Whenever Meren, Bane of the Cairns attacks, exile target creature card from your graveyard. You may cast that card for as long as it remains exiled by sacrificing a creature in addition to paying its other costs.

Flash
You may cast cryptic spells as though they had flash. (Artifacts, enchantments, and modal spells are cryptic.)

Rhapsody {4}{U}{U} (Pay {4}{U}{U} to cast this as a 4/4, or as a sorcery to make it become a 4/4.)
Whenever you cast a noncreature spell, Triumvirate Inductee gets +1/+1 until end of turn. Then if its power is 4 or greater, you may tap or untap target permanent.

Menace, haste

When Eyes in Orbit enters, you may exile another target permanent you control. Return that card to the battlefield under your control at the beginning of the next end step.