msem-instigator

Whenever Alrathan Scholar deals combat damage to a player or planeswalker, draw a card.
{2}{U}: Target creature gains flying until end of turn.

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

If a player would draw a card, instead that player may put a card they own exiled with Arroyo, the Bound into their hand.
{3}: Search target player's library for a card and exile it face down, then that player shuffles. They may look at that card for as long as it remains exiled.

Return up to one target creature card and up to one target land card from your graveyard to your hand.

Siphon (Each -1/-1 counter you put on your creatures up to their remaining toughness while casting this pays for {1}.)
Draw three cards.

At the beginning of each end step, if a player lost 5 or more life this turn, create a 5/5 black Demon creature token with flying.

Gain control of target creature until end of turn. Untap that creature. Then create two 1/1 red Satyr creature tokens with “This creature can't block.” Creatures you control gain haste until end of turn.

Enchant creature or planeswalker
Enchanted permanent has base power 0 and loses all abilities.

Tomb of the Roseblade enters tapped.
{T}: Add {C}.
{X}, {T}, Sacrifice Tomb of the Roseblade: Search your library for an Equipment card with mana value X or less, put it onto the battlefield, then shuffle. Activate only as a sorcery.

Creature spells cost {1} more to cast.
At the beginning of your upkeep, put a decay counter on Stonewood Sanctuary. Then if it has three or more decay counters on it, sacrifice it.

{T}: Add {C}.
{T}: Add one mana of any color. Activate only if you control a creature with a +1/+1 counter on it.

Whenever a creature you control attacks and isn't blocked, 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 that creature, then put the card back or put it into your graveyard.)

Extort (Whenever you cast a spell, you may pay {W/B}. If you do, each opponent loses 1 life and you gain that much life.)
Slums Thug gets +1/+1 and has menace as long as you've gained life this turn.

Flying
When Carrier Familiar enters, create a Vial token. (It's an artifact with “{1}, Sacrifice this and another permanent: Draw a card. Activate only during your turn.”)

Johanna, Skarvith Marshal has first strike as long as it's attacking.
Whenever you attack, you may pay {X}{R/W}{R/W}. When you do, put a +1/+1 counter on each of up to X target attacking creatures. Those creatures gain first strike until end of turn.

Vigilance
If another creature would die, exile it instead.
At the beginning of your upkeep, return each creature card exiled with Arbiter of Endless Summer to the battlefield under its owner's control.

[+1]: Until your next turn, up to one target creature gets -2/-1 and gains “When this creature dies, merge it under Lucien, the Ravenous. He has its abilities.”
[–2]: Merge target creature under Lucien, the Ravenous. He has that creature's abilities.
[–6]: For each card merged with Lucien, create a token that's a copy of that card, except it has haste.

This spell costs {2} less to cast if you sacrificed a Clue this turn.
Target player discards two cards.

When Helmsman's Chart enters, draw a card.
{T}: Until end of turn, target land you control becomes the basic land type of your choice in addition to its other types.

Trample
Art of war — At the beginning of your end step, if Dragon's Wake dealt damage to an opponent this turn, gain control of target land for as long as Dragon's Wake remains on the battlefield.
Tap three untapped creatures you control: Dragon's Wake becomes an artifact creature until end of turn.

Equipped creatures you control get +1/+1.
You may activate equip abilities any time you could cast an instant.
Equip {2}

Flying, haste
Erratic (When this creature dies, reveal the top four cards of your library. Put a creature card that costs less than this revealed this way onto the battlefield and the rest on the bottom of your library in any order.)
When Splitflame Phoenix dies, you may pay {R}. If you do, return it to its owner's hand.

As Sunless Ridge enters, you may tap an untapped creature you control. If you don't, Sunless Ridge enters tapped.
{T}: Add {B} or {R}.

Overgrown Ruins enters tapped.
As Overgrown Ruins enters, choose a color other than green.
{T}: Add {G} or one mana of the chosen color.

Hexproof