msem-instigator

Whenever another creature you control enters, Flightpath Trainee gains flying until end of turn.

Harmony — Target creature gains haste until end of turn.
When Streetside Entertainer enters, harmonize. (Trigger up to one harmony of one permanent you control.)

Changeling (This card is every creature type.)
This creature enters with four -1/-1 counters on it.
Whenever another creature you control enters, if that creature has greater power or toughness than this creature, remove a -1/-1 counter from this creature.

Untap all creatures and lands you control during each other player's untap step.
Ascend {4}{R}{R}{R} ({4}{R}{R}{R}: Exile this creature, then return it to the battlefield transformed. Ascend only as a sorcery.)

Discard a card: Unseen Maniac gets +1/+1 and can't be blocked this turn.
Whenever Unseen Maniac deals combat damage to a player, draw a card.

Flying
Div of the Endless Thought has all activated and triggered abilities of all other permanents on the battlefield.

When Visiting Dignitary enters, gain control of target creature until end of turn. Untap that creature. It gains haste until end of turn.

Controlled Burn deals 2 damage to target player or planeswalker.
At the beginning of your upkeep, you may exile Controlled Burn from your graveyard. If you do, it deals 2 damage to target player or planeswalker.

As an additional cost to cast this spell, exile X cards from your graveyard.
Choose one —
• Target player mills X cards.
• Look at the top X cards of your library. Put one into your hand, and the rest on the bottom of your library in any order.

Whenever Skysworn Savior attacks, you may return another creature you control to its owner's hand. If you do, Skysworn Savior gets +2/+2 and gains flying until end of turn.

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I, II — Audition for green. (Create a 1/1 Construct Actor creature token, a Scout Role giving 2/3 and vigilance, or a Warrior Role giving 3/2 and trample. Roles replace older ones.)
III — Creatures you control get +1/+0 and gain trample until end of turn.
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Destroy target artifact. Smoldering Pages deals damage to that artifact's controller equal to that artifact's mana value.

Whenever you cast a spell, sacrifice a permanent and draw a card.
Exile three cards from your graveyard: Counter target noncreature spell unless its controller pays {1}.

Vanguard — Whenever a creature you control attacks alone, you may exile target instant or sorcery card from your graveyard. If you do, you may cast that spell from exile until your next turn. If that spell would be put into a graveyard, exile it instead.

Tap target creature. It doesn't untap during its controller's next untap step.
Agonize (You may cast this card from your graveyard by putting a -1/-1 counter on a creature you control in addition to paying its other costs. Then exile this card.)

Creatures you control get +2/+1 until end of turn. Embattled creatures you control gain vigilance until end of turn. (A creature is embattled if it has a counter on it or has a permanent you control attached to it.)

Ammbradu Parasite gets +1/+1 as long as you control a Forest.
{4}{G}: Target creature must be blocked this turn if able.

Anomalion enters with a +1/+1 counter on it.
{1}{G}{W}: 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.)

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.

Dance of Dragons deals 4 damage divided as you choose among up to two targets. When one or more permanents dealt damage this way die this turn, draw a card. This ability triggers only once.
Showcase {5}{U}{R} (Then if you cast this for its showcase cost, create a 1/1 red Bard creature token that can't block and exile this. Whenever it attacks, you may cast a free copy of this.)

({T}: Add {U}.)
Aerie's Pillar enters tapped.
Flying
{2}{U}{U}: Aerie's Pillar becomes a creature in addition to its other types until end of turn.

Create a token that's a copy of target nonland permanent you control with mana value X.
Flashback—{U}{U}, Exile cards from your graveyard with exactly X card types among them. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Create three 1/1 red Human creature tokens with haste. Sacrifice those tokens at the beginning of the next end step.
Draw a card.

Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.
Kindle 2—{2}{G} ({2}{G}, Exile this card from your graveyard: Create two 1/1 colorless Elemental creature tokens. Kindle only as a sorcery.)

Whenever you cast an Aura spell, nourish 1. (To nourish 1, either put a +1/+1 counter on this creature or create a 1/1 white Citizen creature token.)