Whenever you cast an instant or sorcery spell, Spellrune Howler gets +2/+2 until end of turn.

Nightbound (If a player casts at least two spells during their own turn, it becomes day next turn.)

Flying

When Spellscorn Coven enters, each opponent discards a card.

Counter target instant or sorcery spell. Its controller reveals cards from the top of their library until they reveal an instant or sorcery card. That player may cast that card without paying its mana cost. Then the player shuffles.

: Change a target of target spell or ability to Spellskite. ( can be paid with either or 2 life.)

Whenever an opponent casts a spell, that player sacrifices a permanent unless they pay .

Assist (Another player can pay up to of this spell's cost.)

When Spellweaver Duo enters, you may return target tapped creature to its owner's hand.

Imprint — When Spellweaver Helix enters, you may exile two target sorcery cards from a single graveyard.

Whenever a player casts a card, if it has the same name as one of the cards exiled with Spellweaver Helix, you may copy the other. If you do, you may cast the copy without paying its mana cost.

Spells that target Spellwild Ouphe cost less to cast.

Sphere of Annihilation enters with X void counters on it.

At the beginning of your upkeep, exile Sphere of Annihilation, all creatures and planeswalkers with mana value less than or equal to the number of void counters on it, and all creature and planeswalker cards in graveyards with mana value less than or equal to the number of void counters on it.

If a black source would deal damage to you, prevent 2 of that damage.

If an artifact would deal damage to you, prevent 1 of that damage.

Spells cost more to cast.

Sphere of the Suns enters tapped and with three charge counters on it.

, Remove a charge counter from Sphere of the Suns: Add one mana of any color.

Flying

Whenever Sphinx Ambassador deals combat damage to a player, search that player's library for a card, then that player chooses a card name. If you searched for a creature card that doesn't have that name, you may put it onto the battlefield under your control. Then that player shuffles.

Flying, ward

Domain — Whenever Sphinx of Clear Skies deals combat damage to a player, reveal the top X cards of your library, where X is the number of basic land types among lands you control. An opponent separates those cards into two piles. Put one pile into your hand and the other into your graveyard. (Piles can be empty.)

You may reveal this card from your opening hand. If you do, scry 3 at the beginning of your first upkeep.

Flying

At the beginning of your upkeep, scry 1.

Kicker (You may pay an additional as you cast this spell.)

Flying

When Sphinx of Lost Truths enters, draw three cards. Then if it wasn't kicked, discard three cards.

Flying, vigilance

Spells your opponents cast that target Sphinx of New Prahv cost more to cast.

This spell can't be countered.

Flying, hexproof

Instant and sorcery spells you control can't be countered.

Flying, lifelink

Whenever you gain life, you get that many (energy counters).

, , Pay X : Draw X cards.

Flying, first strike, vigilance, lifelink, protection from red and from green

Flying

At the beginning of your end step, you gain 3 life if Sphinx Sovereign is untapped. Otherwise, each opponent loses 3 life.

Whenever you cast an instant or sorcery spell, you may put a charge counter on Sphinx-Bone Wand. If you do, Sphinx-Bone Wand deals damage equal to the number of charge counters on it to any target.

Flying

Inspired — Whenever Sphinx's Disciple becomes untapped, draw a card.

Draw two cards.

Addendum — If you cast this spell during your main phase, you gain 2 life.

Whenever you draw a card, target opponent mills two cards. If two nonland cards that share a color were milled this way, repeat this process.

: Draw a card, then discard a card.

Destroy up to one target artifact, enchantment, or creature with flying. Create a Food token. (It's an artifact with ", , Sacrifice this artifact: You gain 3 life.")

Enchant creature

Enchanted creature gets +1/+1 and has reach. (It can block creatures with flying.)

Umbra armor (If enchanted creature would be destroyed, instead remove all damage from it and destroy this Aura.)

Equipped creature gets +0/+2 and has reach. (It can block creatures with flying.)

Equip (: Attach to target creature you control. Equip only as a sorcery.)

Untap target creature. It gets +2/+4 and gains reach until end of turn. (It can block creatures with flying.)

Spike Cannibal enters with a +1/+1 counter on it.

When Spike Cannibal enters, move all +1/+1 counters from all creatures onto it.

Spike Drone enters with a +1/+1 counter on it.

, Remove a +1/+1 counter from Spike Drone: Put a +1/+1 counter on target creature.

Spike Hatcher enters with six +1/+1 counters on it.

, Remove a +1/+1 counter from Spike Hatcher: Put a +1/+1 counter on target creature.

, Remove a +1/+1 counter from Spike Hatcher: Regenerate Spike Hatcher.

Spike Rogue enters with two +1/+1 counters on it.

, Remove a +1/+1 counter from Spike Rogue: Put a +1/+1 counter on target creature.

, Remove a +1/+1 counter from a creature you control: Put a +1/+1 counter on Spike Rogue.

Spike Tiller enters with three +1/+1 counters on it.

, Remove a +1/+1 counter from Spike Tiller: Put a +1/+1 counter on target creature.

, Remove a +1/+1 counter from Spike Tiller: Target land becomes a 2/2 creature that's still a land. Put a +1/+1 counter on it.

Spike Worker enters with two +1/+1 counters on it.

, Remove a +1/+1 counter from Spike Worker: Put a +1/+1 counter on target creature.

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)

Flash

, , Sacrifice Spiked Pit Trap: Choose target creature, then roll a d20.

1–9 | Spiked Pit Trap deals 5 damage to that creature.

10–20 | Spiked Pit Trap deals 5 damage to that creature. Create a Treasure token.

Spikefield Cave enters tapped.

: Add .

: Spikeshot Elder deals damage equal to its power to any target.

Flying

Sacrifice Spiketail Drake: Counter target spell unless its controller pays .

Flying (This creature can't be blocked except by creatures with flying or reach.)

Sacrifice Spiketail Hatchling: Counter target spell unless its controller pays .

Spectacle (You may cast this spell for its spectacle cost rather than its mana cost if an opponent lost life this turn.)

Put target creature on top of its owner's library, then fateseal 2. (To fateseal 2, look at the top two cards of an opponent's library, then put any number of them on the bottom of that player's library and the rest on top in any order.)

Cast this spell only during combat.

Untap target creature you don't control and gain control of it. It gains haste until end of turn. At the beginning of the next end step, sacrifice it. If you do, you gain life equal to its toughness.

Sunburst (This enters with a +1/+1 counter on it for each color of mana spent to cast it.)

Remove two +1/+1 counters from Spinal Parasite: Remove a counter from target permanent.

Whenever Spincrusher blocks, put a +1/+1 counter on it.

Remove a +1/+1 counter from Spincrusher: Spincrusher can't be blocked this turn.

When Spine of Ish Sah enters, destroy target permanent.

When Spine of Ish Sah is put into a graveyard from the battlefield, return Spine of Ish Sah to its owner's hand.

Morph (You may cast this card face down as a 2/2 creature for . Turn it face up any time for its morph cost.)

Hexproof (This creature can't be the target of spells or abilities your opponents control.)

Whenever Spined Megalodon attacks, scry 1. (Look at the top card of your library. You may put that card on the bottom.)