msem-instigator

Enchant creature
As Legacy of Siltbottom enters, choose a creature type.
Enchanted creature gets +3/+3 and is the chosen type in addition to its other types.

Return target creature card with mana value 3 or less from your graveyard to the battlefield. Put a +1/+1 counter on it. It gains indestructible until end of turn.

Search your library for a creature card with mana value 3 or less, put it onto the battlefield, then shuffle. It gains haste until end of turn. Return it to your hand at the beginning of the end step.

Flying (This creature can't be blocked except by creatures with flying or reach.)
Whenever Mindscreech Drake deals combat damage to a player, that player mills three cards.

Menace (This creature can't be blocked except by two or more creatures.)
Whenever Mausoleum Revenant deals damage to a player, create a 2/2 black Zombie creature token.

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
When Northwind Master enters, you may have another target creature you control gain prowess until end of turn.

{T}: Adept Fisherman voyages. (If it isn't blocking or targeted by another spell or ability, it phases out.)
Whenever Adept Fisherman phases in, you gain 2 life.

Skin from Bone deals damage to target creature equal to your fealty to Mountains. (Each Mountain you control counts towards your fealty to Mountains.)

Put a -1/-1 counter on target creature. Purge the Harbor deals 1 damage to that creature's controller.

Vanishing 1 (This permanent enters with a time counter on it. At the beginning of your upkeep, remove a time counter from it. When the last is removed, sacrifice it.)
When Flesh to Rot enters or the last time counter is removed from it, all creatures get -3/-3 until end of turn.

({T}: Add {R}, {W}, or {B}.)
Desolate Dominion enters tapped.

Whenever you draw a card, put a +1/+1 counter on Acolyte of Water.
Surpass {5}{U} ({5}{U}: Transform this creature. This costs {1} less to activate for each counter on it. Activate only as a sorcery.)

Search your library for a basic land card and put it onto the battlefield tapped, then shuffle. You gain 1 life for each land you control.

{1}, {T}, Sacrifice Soul-Synthesizer: Look at the top seven cards of your library. You may reveal a card with an activated ability from among them and put it into your hand. Put the rest on the bottom of your library in any order.

Enchant creature
Enchanted creature gets +2/+2 and has lifelink.

As an additional cost to cast this spell, you may tap
any number of untapped Angels and/or Nephilim you control. This spell costs {1} less to cast for each creature tapped this way.
Flying, vigilance
When Empyrean Scholar enters, each creature tapped to pay its additional cost becomes a 4/4 Angel creature with flying and vigilance. (This effect lasts indefinitely.)

Menace
Whenever one or more cards leave your graveyard or Watchers of the Veil leaves your graveyard, you may draw a card. If you do, discard a card.

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)

Creatures you control get +2/+2 and gain trample until end of turn. If you cast this spell from exile, creatures you control get an additional +2/+2 until end of turn.
Prophecy {2}{G}{G} (Once each turn, you may exile a card with prophecy as you reveal it. When you do, you may cast it for its prophecy cost as long as it's exiled.)

Indestructible
Whenever a creature an opponent controls dies, put five +1/+1 counters on Scion of Death.

Whenever Pelaski Valiant becomes tapped, target creature gets +1/+1 until end of turn.

When Thoughtslick Engineer enters, each player discards a card at random.

For each legendary permanent you control, this spell costs one mana of one of that permanent's colors less to cast. This effect reduces only the amount of colored mana you pay.
For each color, create a token that's a copy of a different legendary permanent you control of that color, except the token isn't legendary.
Exile The Tale of Kings.

Trample
Whenever Arisen Tyrant attacks, mill three cards, then you may exile a card from your graveyard. You may cast a copy of the exiled card without paying its mana cost if the spell's mana value is 3 or less.
If Arisen Tyrant would die, exile it instead.

Trample, ward {1}
Whenever Stardust Surveyor deals combat damage to a player, you may mill cards until you mill a creature card. When you do, return target creature card from your graveyard to your hand.