msem-instigator

Primal {3}{U}{U} (During your turn, you may cast this spell for {3}{U}{U} instead of playing a land.)
Draw a card for each land you control, then discard that many cards unless this spell was cast for its primal cost.

Prowess
Each instant and sorcery card with mana value 3 or less in your hand has inscribe. The inscribe cost is equal to its mana cost increased by {1}{U/R}. (Pay that card's mana cost increased by {1}{U/R}: Exile that 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.)

Enchant creature
You control enchanted creature.
When Shahmaran's Captivation enters, untap enchanted creature. It gains haste until end of turn.

When you unveil Shining Elementalist, creatures can't block this turn.

Flying
Instant and sorcery spells you cast cost {1} less to cast.
Whenever you cast your second spell each turn, draw a card.

Heretic (Whenever you cast a spell that doesn't share a color with this creature, it gets +1/+1 until end of turn.)
When Shoring Naiad enters, if {U} was spent to cast it, you may return an instant or sorcery card from your graveyard to your hand.

{T}: Add {U} or {R}.
{T}, Sacrifice Sigil of Ingenuity: Add {U}{R}.

Enchant creature
When Silent Call enters, draw a card.
Enchanted creature attacks each combat if able.

Whenever you draw a card, Silverblood Aspirant gets +1/+1 until end of turn.
{1}{R}, Discard a card: Draw a card.

Prowess
Whenever Siv Katari, Rebel Technician attacks, create a tapped and attacking X/X colorless Construct artifact creature token with prowess, where X is Siv Katari's power. Exile that token at end of combat.

Slipstream Horizon enters tapped.
{T}: Add {U} or {R}.
{U}{R}, {T}, Sacrifice Slipstream Horizon: Conjure a card named Data-Point into your hand. (It's a sorcery that costs {2} with “Draw a card.”)

Create a 4/4 red Dragon creature token with flying.
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.)

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Whenever a creature you control attacks, it deals 1 damage to target opponent.

Flying
Whenever Spellgorger Elemental attacks, discard a card at random. If an instant or sorcery card is discarded this way, Spellgorger Elemental deals 3 damage to any target. Otherwise, draw a card.

Haste
Whenever Spellmaw Crocodile deals combat damage to a player, draw a card.
Discard a card: Spellmaw Crocodile can't be blocked this turn.

Spined Spire enters tapped.
{T}: Add {U} or {R}.
{1}{U}{R}: Until end of turn, Spined Spire becomes a Lizard creature with menace in addition to its other types.
Scavenge {1}{U}{R}

Draw two cards, then discard a card.
Whenever you cast an instant or sorcery spell, if Spirit Script is in your graveyard, you may have it become a copy of that spell until end of turn.

Defender
Prismatic — Whenever you cast a multicolored spell, Squall Serpent gets +1/+1 until end of turn and can attack this turn as though it didn't have defender.

Menace
Stalker of Myth gets +1/+0 for each creature you control with chronicle.
{2}, Remove a counter from a permanent you control: Draw a card, then discard a card.

({T}: Add {U} or {R}.)
Steamlit Peaks enters tapped.
{1}, {T}: Add {U}{U} or {R}{R}.

Prowess
Whenever Steamwalker attacks, you may discard a card. If you do, draw a card, then catalyze. (The next spell you cast this turn costs {1} less to cast.)

Flying
Whenever you cast your first spell each turn, add {U}{U}, {U}{R}, or {R}{R}.
Whenever you cast your second spell each turn, investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)
Whenever you cast your third spell each turn, Stirring Igmel deals 3 damage to each opponent.

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.

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