msem-instigator

Exile up to three target instant and/or sorcery cards from your graveyard. Until end of turn, you may cast cards exiled this way.
Exile Speedreading.

Counter target noncreature spell unless its controller pays {2}.

Flash (You may cast this spell any time you could cast an instant.)
When Spell Shackle enters, exile target instant or sorcery spell. (That spell won't resolve.)
{1}{U}, Sacrifice Spell Shackle: Cast the exiled card without paying its mana cost.

Instant and sorcery spells your opponents cast cost {1} more to cast.

Hexproof
Whenever an opponent casts a noncreature spell, put a +1/+1 counter on Spellbane Vulpine.

When Spellblade enters, you may exile an instant card with mana value 2 or less from your hand.
At the beginning of your end step, if equipped creature dealt damage to an opponent this turn, you may copy the exiled card. If you do, you may cast the copy without paying its mana cost.
Equip {2}

Flying
Spelldust Sprite gets +1/+1 as long as you control four or more creatures with flying.
If you would create a token, you may instead create a token that's a copy of Spelldust Sprite, except it doesn't have this ability.

Spirited (When this creature enters, you may activate one of its activated abilities without paying its cost.)
{2}{R}{R}: If an instant or sorcery source you control would deal damage to a permanent or player this turn, it deals that much damage plus 2 instead.

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

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.

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

Haste
Whenever Spellslinger Elf deals combat damage to a player, draw a card, then you may cast a card from your hand with mana value 3 or less without paying its mana cost.

When Spellslinger's Gauntlet enters, exile an instant or sorcery card with mana value 3 or less from your hand.
Whenever equipped creature attacks, you may copy the exiled card. If you do, you may cast the copy without paying its mana cost.
Equip {3}

Whenever this creature enters, attacks, or leaves the battlefield, choose one that hasn't been chosen.
• Return another target nonland permanent to its owner's hand.
• Draw two cards.
• Create three 1/1 blue Bird creature tokens with flying.
• Add {U}{U}{U}{U}. You can't spend this mana to cast creature spells.

Cadence (Whenever you cast a spell, if its mana value is greater than this creature's power, put a +1/+1 counter on this creature.)
Remove a +1/+1 counter from Spellsword Elite: The next noncreature spell you cast this turn costs {1} less to cast.

Defender, flying
Cadence (Whenever you cast a spell, if its mana value is greater than this creature's power, put a +1/+1 counter on this creature.)
Remove a +1/+1 counter from Spellwork Bulwark: It loses defender and gains hexproof and indestructible until end of turn.

{1}, {T}, Exile Sphere of Sorcery: Return target noncreature, nonland card from your graveyard to your hand.
{8}, {T}, Exile Sphere of Sorcery: Return any number of target noncreature, nonland cards from your graveyard to your hand.

Flying
When Sphinx of Riddles enters, secretly choose a card name. You may reveal the chosen name any time.
Whenever a spell an opponent controls with the chosen name resolves, you may draw two cards.

Flying
{X}{U}: Gain control of target nonland permanent with mana value X until Sphinx of Supremacy leaves the battlefield. Activate only as a sorcery.

Whenever Sphinx's Grandeur or another enchantment you control enters, create a 1/1 white Soldier creature token.
Creatures you control get +1/+1.

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}

Spinerock Canyon enters tapped unless you control a basic land.
{T}: Add {R} or {W}.

Haste
Ward—Sacrifice a creature.
Spinning Gears Abomination enters with X +1/+1 counters on it.
Spinning Gears Abomination can't attack alone.

({T}: Add {R} or {W}.)
Spiraling Canyon enters tapped unless you control a basic Mountain or a basic Plains.