msem-instigator

Trample, haste
Thriving Hydra enters with four +1/+1 counters on it.
When Thriving Hydra enters, for each other creature you control, put X +1/+1 counters on that creature, where X is four minus its power.
Whenever Thriving Hydra attacks, double the number of +1/+1 counters on each creature you control.

As an additional cost to cast this spell, sacrifice a land.
Creatures you control get +1/+1 and gain trample until end of turn for each land you control.

Each creature you control enters with an additional +1/+1 counter on it.
Each planeswalker you control enters with an additional loyalty counter on it.

Whenever a permanent an opponent controls becomes the target of a spell you control, put a progress counter on Throne of the West.
[PROGRESS 2+] {T}: Gain control of target permanent until end of turn. Untap it. It gains haste until end of turn.
[PROGRESS 5+] You can't lose control of permanents.

Exile any number of target creatures and/or planeswalkers you control. You gain 1 life for each card exiled this way, then return them to the battlefield under your control.

The next creature spell you cast this turn may be cast as though it had flash and costs {1} less to cast. If it entering the battlefield causes a triggered ability of it to trigger, that ability triggers an additional time.

Renown 1 (When this creature deals combat damage to a player, if it isn't renowned, put a +1/+1 counter on it and it becomes renowned.)
Thuggish Detective can't be blocked by more than one creature.
When Thuggish Detective becomes renowned, you may destroy target noncreature permanent.

Augmented — When you cast this spell, if it's your turn and you've spent {W}{U}{B}{R}{G} to cast spells this turn, copy it twice. You may choose new targets for the copies.
Thunder Road deals 3 damage to any target. You gain 3 life.

This spell costs {X} less to cast, where X is the greatest power among creatures you control.
Trample

Whenever Thundering Towershell attacks, return a creature card with mana value 5 or less from a graveyard to the battlefield under your control. Trigger a death knell of that creature.

Flying
Spirited (When this creature enters, you may activate one of its activated abilities without paying its cost.)
{3}{R}{R}, {T}: Exile an instant card with mana value 3 or less from your graveyard, then cast a copy of a card exiled with Thunderlash Mystic without paying its mana cost.

Flash
Whenever Thundermane Fox enters or attacks, target creature you control gains double strike until end of turn.

Target creature gains hexproof and trample until end of turn. If Thunderous Charge was cast from exile, that creature gets an additional +4/+4 until end of turn.
Orchestrate {G}{G} (You may exile this card from your hand anytime you could cast a sorcery for its orchestrate cost. When you next resolve a spell, you may cast this from exile without paying its mana cost.)

Primal {2}{R}{R} (During your turn, you may cast this spell for {2}{R}{R} instead of playing a land.)
Flying, prowess
At the beginning of your end step, if you didn't cast a spell this turn, sacrifice Thunderstride.

Flying
Tianyuren Skycharter has hexproof as long as you control a storied permanent. (Enchantments and legendary permanents are storied.)

As an additional cost to cast this spell, tap any number of untapped storied permanents you control.
Return X target creatures to their owner's hand, where X is one plus the number of permanents tapped this way.

Permanents you control gain indestructible until end of turn. Untap each creature you control.
Cycling {W} ({W}, Discard this card: Draw a card.)

Embellish {3}{B} (If you cast this spell for {3}{B}, create a 1/1 blue Thopter artifact creature token with flying when it enters.)
Tidehollow Lich can't block.
You may cast Tidehollow Lich from your graveyard as long as you control an artifact creature.

Experience (Whenever this creature attacks, if it has fewer than three +1/+1 counters on it, put a +1/+1 counter on it.)
When Tidepool Turtle has three or more +1/+1 counters on it, remove them all and transform it.

Kicker {X}{U} (You may pay an additional {X}{U} as you cast this spell.)
When Tidetwister Mage enters, if it was kicked, return all other creatures with power X or less to their owners' hands.

Create X 0/1 green Plant creature tokens, then distribute X +1/+1 counters among any number of creatures you control.

Flying, prowess
Whenever you cast a noncreature spell, reveal the bottom two cards of your library. Target opponent chooses one of them. Put that card on the bottom of your library and the rest into your hand.

As Timber Range enters, you may pay 2 life. If you don't, Timber Range enters tapped.
{T}, Sacrifice Timber Range: Search your library for a Mountain or Forest card, put it onto the battlefield, then shuffle.

Take an extra turn after this one. Exile Time if it wasn't fused.
Fuse (You may cast one or both halves of this card from your hand.)

Instant and sorcery spells you control have leitmotif. (Exile that spell as it resolves if you cast it from your hand. When you next cast a spell that shares a color with that card, you may cast it from exile without paying its mana cost.)