msem-instigator

This spell costs {2} less to cast if you control a legendary creature.
Search your library for a creature or land card, reveal it, put it into your hand, then shuffle.

Exile target creature. That creature's controller may have each player draw a card.

Haste
Storm Entity enters with a +1/+1 counter on it for each other spell cast this turn.

Whenever a permanent you control becomes tapped, Storm Servant gets +1/+1 until end of turn.

Until end of turn, creatures target player controls lose all abilities and have base power and toughness 0/2.
Inscribe {4}{B}{B} ({4}{B}{B}: Exile this card from your hand inscribed on a creature you control. Whenever that creature attacks, its controller may cast a copy of the inscribed card without paying its mana cost. Inscribe only as a sorcery.)

You may pay {1}{R}{R} and tap an untapped Knight you control rather than pay this spell's mana cost.
Target untapped creature you don't control blocks this turn if able. Other creatures can't block this turn.

Mill five cards, then for each of those cards, a creature you control salvages that card unless an opponent pays 3 life. (Exile it from your graveyard until that creature leaves the battlefield. Whenever that creature deals combat damage to a player, put a card it salvaged into your hand.)

Colossal 3—{4}{R} (You may cast this for its colossal cost to have it enter with three +1/+1 counters; or pay {4}{R} as a sorcery: Put three +1/+1 counters on it if it has none.)
When Storm-Eye Salamander's colossal ability puts one or more counters on it, exile the top three cards of your library. Until the end of your next turn, you may play one of those cards.

Whenever you cast an instant or sorcery spell, you may attach Stormbreaker's Edge to target creature you control.
Equipped creature gets +3/+0.
Equip {3}

Stormbred Elemental gets +1/+1 as long as you control an Island.
{U}: Stormbred Elemental gains flying until end of turn.

Flying, haste
Whenever you cast an instant or sorcery spell, create a token that's a copy of Stormcall Thunderbird.

Beckon Drake {2}{U}{U} ({2}{U}{U}: This noncreature Deity permanently becomes a Drake creature in addition to its other types.)
Flying
Other creatures you control with flying get +1/+1.

When you cast this spell from your hand, return it to your hand.
Choose one —
• Stormcalling deals 4 damage to any target.
• Exile target artifact.

Whenever equipped creature attacks, it deals damage to defending player equal to the number of instant and sorcery cards in your graveyard.
Equip {2}

Whenever one or more creatures you control attack, you may put a progress counter on Stormcannon Testing.
[PROGRESS 2-3] {T}: Target creature gets +2/+0 until end of turn.
[PROGRESS 4+] {T}: Target creature gets +2/+0 and gains double strike until end of turn.

{T}: Add {C}.
{T}, Exile two cards from your graveyard: Add {U} or {R}.

Stormcharged Pyre enters tapped unless you have two or more opponents.
{T}: Add {U} or {R}.

Flying, haste
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)

Flying
Stormcloud Drake gets +1/+0 for each instant and sorcery card in your graveyard.
Whenever Stormcloud Drake attacks, tap target creature defending player controls.

Other artifacts you control have ward {1}.
Overcast — Whenever you cast an artifact creature spell, if {C} was spent to cast it, it enters with an additional +1/+1 counter on it.

Vigilance
{4}{U}: Draw a card.

Prowess, haste

Stormsurge deals 3 damage to any target.
Orchestrate {R} (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.)

Whenever one or more creatures you control deal combat damage to a player, exile a nonland card from that player's graveyard. Copy it. You may cast the copy. (You still pay its costs, including color. Copies of permanents enter as tokens.)

At the beginning of your upkeep, you may pay 2 life. If you do, exile the top card of target opponent's library. If a nonland card is exiled this way, copy it. You may cast the copy. (You still pay its costs, including color. Copies of permanents enter as tokens.)