msem-instigator

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)

Glitch {2} (Remove one [restriction] for each time you pay the glitch cost.)
Improbable Aim deals damage to target creature or planeswalker equal to the number of [instant and sorcery] cards in your graveyard.

Other creatures you control get +1/+0.
{R}{W}: Create a 1/1 red and white Warrior creature token. That token gains haste. Exile it at the beginning of the next end step. Activate only as a sorcery.

{2}{R}, Sacrifice a creature: Target creature can't block this turn.

Enchant player
When Scaleblight's Quarry enters, you may have target creature you control deal damage equal to its power to target creature enchanted player controls.
Whenever enchanted player becomes the target of a spell you control, you gain 1 life.

Trample
Cavern Carver has haste as long as you control another creature with flash or haste.

Glorious end — When Seeker of Conto Sika dies, if it was tapped, draw a card.

Whenever a creature you control dies, put a legacy counter on Testament to Heroism.
{T}: Add {C}.
{T}, Remove a legacy counter from Testament to Heroism: Add one mana of any color.

When this creature enters, search your library for a creature card with mana value 1 or less, reveal it, put it into your hand, then shuffle.
Arise {2}{W} ({2}{W}, Exile this from your graveyard as a sorcery: Create a black token copy of it that's also a Zombie and can't block.)

Trample
Whenever Simian Sentinel attacks, it gets +X/+0 until end of turn, where X is the number of lore counters on Sagas you control.

Synchronous Battle Armor and equipped creature get +1/+1 for each artifact you control.
Whenever equipped creature attacks, tap up to three target creatures.
Reconfigure {3}{U}{U} ({3}{U}{U}: Attach to target creature you control; or unattach from a creature. Reconfigure only as a sorcery. While attached, this isn't a creature.)

Whenever equipped creature deals combat damage to a player, draw a card.
Whenever a Vehicle you control becomes a creature, you may attach Planar Uplink to it.
Equip {U}

Whenever you cast a spell you don't own, you may pay {1}{U}. If you do, put target nonland permanent on top of its owner's library.
{2}{B}: Exile the top card of target opponent's library face down. You may look at and cast that card for as long as it remains exiled, and you may spend mana as though it were mana of any type to cast that spell.

Engorge (As this enters, mill three cards, then exile a card from among the milled cards.)
Whenever an instant or sorcery card you own is exiled from anywhere, you gain 1 life.

Flying
Whenever Revived Pterosaur deals combat damage to an opponent, that player discards a card.
{4}{B}{B}, Discard two cards: Return Revived Pterosaur from your graveyard to the battlefield tapped.

Engorge (As this enters, mill three cards, then exile a card from among the milled cards.)
Spells you cast that share a type with the card Chillwhisper Witch engorged cost {1} less to cast.

Desert Wurms can't be blocked by creatures with flying.
When Desert Wurms enters, create two 6/6 red Wurm creature tokens with “This creature can't be blocked by creatures with flying.”
When Desert Wurms is put into a graveyard from anywhere, shuffle it into its owner's library.

Target opponent reveals their hand. You choose a nonland card from it. That player discards that card. You lose 2 life unless that player is cursed.

Tap up to two target creatures.
Permutate. (You may remove a counter from a creature you control. If you do, put two +1/+1 counters on a different creature you control.)

Enchant creature
Enchanted creature gets +3/+3 and has trample.

Bestial Mob's power and toughness are each equal to the number of creatures you control.
Whenever Bestial Mob deals combat damage to a player, destroy target creature with toughness less than Bestial Mob's power.

Hexproof, vigilance, lifelink

Whenever you cast a spell that doesn't share a color with Pond Tenders, you may put target card from your graveyard on the bottom of your library.

Counter target instant or sorcery spell. If that spell is countered this way, exile it instead of putting it into its owner's graveyard.

Whenever a player casts a creature spell, they sacrifice a creature.
Revive—{3}{B}{G}, Sacrifice a creature. ({3}{B}{G}, Sacrifice a creature, Exile this card from your graveyard: Create a token that's a copy of it except it has no mana cost. Revive only as a sorcery.)