msem-instigator

When Sentient Contraption enters, create a 1/1 colorless Thopter artifact creature token with flying.

Glacial Vista enters tapped.
{T}: Add {W} or {U}.
{1}, {T}: Add one mana of any color.

When Smuggler of the Santriza enters, you may discard a card. If you do, draw a card.

[+1]: Look at the top two cards of your library. Put one of them into your hand and the other into your graveyard.
[–2]: Return target card from your graveyard to the battlefield face down.
[–6]: Turn any number of face-up nonland permanents of your choice face down.

Other Merfolk you control get +1/+1.
{1}{U}: Target Merfolk gains slipstream until end of turn. (Creatures with slipstream can't be blocked as long as only creatures with slipstream are attacking.)

Once each turn, when you search your library, you may add {B}{B}.

Chronicle (As this enters and after your draw step, add a lore counter. Stop after III.)
[Lore I-II] Target creature you control can't be blocked by creatures with power 2 or less this turn.
[Lore III] Draw a card.

Flying
Prophecy {0} (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.)

Whenever you activate one of Ai's loyalty abilities, create a 2/2 colorless Soldier artifact creature token with that ability, except it costs +1 to activate.
[+1]: Ai deals 1 damage to target player or planeswalker. You gain 1 life.
[–3]: Draw a card. You lose 1 life.
[–7]: Each opponent sacrifices a permanent and discards a card.

{3}{G}, {T}: Create a 2/2 green Wolf Elemental creature token.

Whenever Poignant Hydra deals combat damage to a player, put a +1/+1 counter on it.
Creature spells you cast with power less than Poignant Hydra's power cost {1} less to cast.

Vigilance
Sha'Iv's Emissary gets +1/+1 as long as you control a blue or red permanent.

Frondpond Grotto enters tapped unless you played it from exile.
{T}: Add {U} or {B}.

{T}: Add one mana of any color. You can't spend this mana to cast spells with mana value 3 or greater.
Revive {2}{G} ({2}{G}, Exile this card from your graveyard: Create a token that's a copy of this card, except it has no mana cost. Activate this ability only any time you could cast a sorcery.)

Enchant player
At the beginning of enchanted player's upkeep, they choose one —
• That player reveals their hand and discards a card.
• That player discards a card at random.

Siphon (Each -1/-1 counter you put on your creatures up to their remaining toughness while casting this pays for {1}.)
Counter target spell unless its controller pays {4}.

This spell can't be countered.
Draw a card.
Reprise {2}{U} (As you cast an instant or sorcery spell, you may exile one card with reprise from your graveyard and pay its reprise cost. If you do, add its effects to that spell.)

Whenever another creature you control leaves the battlefield, put a +1/+1 counter on Zealot of Mahara.
Surpass {5}{W} ({5}{W}: Transform this creature. This costs {1} less to activate for each counter on it. Activate only as a sorcery.)

Search your library for up to two cards with different names and reveal them. Target opponent chooses one of those cards. Put the chosen card into your graveyard and the rest into your hand. Then shuffle.

After a player chooses two or more modes while casting a spell, you may pick one of those modes. That mode is no longer chosen. (That player doesn't pick targets or pay costs related to that mode. If a mode is chosen multiple times, only one instance of that mode is lost.)

Trial 3 (As you cast this spell, an opponent of your choice may pay 3 life. If they don't, they fail the trial.)
When Steeple Deadeye enters, if the trial was failed, you gain 3 life and put a +1/+1 counter on Steeple Deadeye.

Scoured Barrens enters tapped.
When Scoured Barrens enters, you gain 1 life.
{T}: Add {W} or {B}.

Haste
Sixpod Sprinter can't be blocked except by creatures with flying or reach.

Once each turn, you may cast a creature you control from the battlefield.
(You can cast its Adventure this way.)

Hellfire Caverns enters tapped.
{T}: Add {R}.
{2}{R}: Until end of turn, Hellfire Caverns becomes a 3/3 Devil creature with menace. Activate only if you're horrific.