msem-instigator

Each creature gets -X/-X until end of turn. Destroy each artifact and enchantment with mana value X or less.

Flying
Whenever Skyflock Warrior or another creature you control with flying attacks, create a 1/1 white Bird creature token with flying.

Flying, trample, haste
Whenever a land you control enters or a land is put into your graveyard from the battlefield, Skyscreecher Dragon deals 2 damage to each opponent.

Flying
When Skystream Mantas is returned to your hand from the battlefield, draw two cards.

Creatures can't attack you unless their controller pays {2} for each creature they control that's attacking you.
{3}{W}{U}: Tap target creature and put a +1/+1 counter on Solitary Guardian.

Whenever you cast a noncreature spell, you may pay {U}. If you do or the spell was cast from your graveyard, draw a card.

You may cast this spell without paying its mana cost if it's the only card in your hand.
Counter target spell.

Spires of Caulte enters tapped.
{T}: Add {B} or {R}.
{B}{R}: Until end of turn, Spires of Caulte becomes a 3/2 black and red Construct creature with with menace and “Whenever this creature attacks or blocks, torment yourself.” It's still a land. (To torment yourself, lose 3 life unless you discard a card or sacrifice a nonland permanent.)

Lifelink
When Stalked Healer enters, investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)

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.

Flying
Whenever you cast a noncreature spell, note its mana value.
When Strix of Dark Omens dies, draw a card and create a 1/1 blue Bird creature token with flying for each different number noted with it.

Target creature gets -3/-3 until end of turn. If that creature would die this turn, exile it instead.

You may pay {W}{U}{B}{R}{G} rather than pay this spell's mana cost.

Sunlit Fissure enters tapped.
{T}: Add {G} or {W}.
{2}{G}{W}: Until end of turn, Sunlit Fissure becomes a 3/5 green and white Elemental creature with with vigilance and “Whenever this creature attacks or blocks, torment yourself.” It's still a land. (To torment yourself, lose 3 life unless you discard a card or sacrifice a nonland permanent.)

Flash
Flying
When Sunset Herald enters, if it was cast, return to the battlefield all creature cards from your graveyard that were put there from the battlefield this turn.

As an additional cost to cast this spell, torment yourself. (You lose 3 life unless you discard a card or sacrifice a nonland permanent.)
Destroy target creature.

Flying
When Syrina, the Dragon Queen enters, gain control of target nonland permanent for as long as you control Syrina, the Dragon Queen.
{2}{U}: Exile Syrina, the Dragon Queen. Return her to the battlefield at the beginning of the next end step.

[+2]: Create a 2/2 red Werewolf creature token with first strike and haste.
[–3]: Tanya deals 3 damage to each creature that's not a Wolf or a Werewolf.
[–8]: For each permanent your opponents control, that player sacrifices it unless they have Tanya deal 2 damage to them.

[+1]: Tanya, the Mooncursed becomes a legendary 3/1 red Werewolf creature with first strike until end of turn.
[–2]: Tanya, the Mooncursed deals 3 damage to target creature or planeswalker.
[–4]: Destroy target nonbasic colorless permanent.

Return target creature card from your graveyard to the battlefield.
Fabled {2}{B} (Then if you cast this for its fabled cost, put it onto the battlefield transformed attached to that creature.)

This spell costs {1} less to cast for each ten cards in your library.
Take an extra turn after this one.
Exile Temporal Insight.

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.

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Put all creature cards from your graveyard onto the battlefield.
II — Creatures you control gain lifelink until end of turn.
III — Destroy all creatures.

The Flames Approach deals 3 damage to any target.
Memento {3}{R}{R} (You may cast this from your graveyard for {3}{R}{R}. If you do, put it onto the battlefield transformed after it resolves. Exile it if it would leave the battlefield or not resolve.)

Flying
You pay {0} to cast your first spell each turn rather than its mana cost. If you cast a spell with {X} in its mana cost this way, X is 8.