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.
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.
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 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.
“Slingers should be wary of the chaos these elves wield. Elves that appear alone and unarmed will quickly outnumber and outgun the unprepared.”
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}
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.
Spellwoven Monster can't be the target of spells or abilities in any zone. As you cast an instant or sorcery spell, reveal cards from the bottom of your library until you reveal an instant or sorcery card. You may add that card's effects to that spell. Then shuffle.
{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 If a nonland permanent an opponent controls would be returned to its owner's hand, instead gain control of it for as long as you control Sphinx Paramount.
There is no fleeing the authority of the sphinxes.
Flying When Sphinx of Ill Omens enters, return target permanent to its owner's hand. Discard a card: Target creature or player gains hexproof until end of turn.
Flying, ward {3} Whenever Sphinx of Myriad Futures attacks, look at the top three cards of your library and reveal one of them. The defending player may have you put the revealed card into your hand. If they don't, put the other two cards into your hand. Then put the remaining cards into your graveyard.
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.
If an ability of a creature or planeswalker an opponent controls was activated this turn, you may pay {1}{B} rather than pay Spike Wall Trap's mana cost. Destroy target creature or planeswalker.
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}