Sphere of Resistance

Thalia, Guardian of Thraben

First strike
Noncreature spells cost {1} more to cast.

Thorn of Amethyst

Noncreature spells cost {1} more to cast.

Fellwar Stone

{T}: Add one mana of any color that a land an opponent controls could produce.

Lodestone Golem

Nonartifact spells cost {1} more to cast.

Smokestack

At the beginning of your upkeep, you may put a soot counter on Smokestack.
At the beginning of each player's upkeep, that player sacrifices a permanent of their choice for each soot counter on Smokestack.

Gruul Signet

Crystal Quarry

{T}: Add {C}.
{5}, {T}: Add {W}{U}{B}{R}{G}.

Azorius Signet

Fist of Suns

You may pay {W}{U}{B}{R}{G} rather than pay the mana cost for spells you cast.

Jhoira of the Ghitu

{2}, Exile a nonland card from your hand: Put four time counters on the exiled card. If it doesn't have suspend, it gains suspend. (At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost. If it's a creature, it has haste.)

Izzet Signet

Gaddock Teeg

Noncreature spells with mana value 4 or greater can't be cast.
Noncreature spells with {X} in their mana costs can't be cast.

Rakdos Signet

Monastery Siege

As Monastery Siege enters, choose Khans or Dragons.
• Khans — At the beginning of your draw step, draw an additional card, then discard a card.
• Dragons — Spells your opponents cast that target you or a permanent you control cost {2} more to cast.

Academy Loremaster

At the beginning of each player's draw step, that player may draw an additional card. If they do, spells they cast this turn cost {2} more to cast.

Dovin, Hand of Control

Artifact, instant, and sorcery spells your opponents cast cost {1} more to cast.
−1: Until your next turn, prevent all damage that would be dealt to and dealt by target permanent an opponent controls.

Boros Signet

Aura of Silence

Artifact and enchantment spells your opponents cast cost {2} more to cast.
Sacrifice Aura of Silence: Destroy target artifact or enchantment.

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice Commander's Sphere: Draw a card.

Grand Arbiter Augustin IV

White spells you cast cost {1} less to cast.
Blue spells you cast cost {1} less to cast.
Spells your opponents cast cost {1} more to cast.

Glowrider

God-Pharaoh's Statue

Spells your opponents cast cost {2} more to cast.
At the beginning of your end step, each opponent loses 1 life.

Dimir Signet

Thought Vessel

You have no maximum hand size.
{T}: Add {C}.

Vryn Wingmare

Flying
Noncreature spells cost {1} more to cast.

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Defense Grid

Each spell costs {3} more to cast except during its controller's turn.

Golgari Signet

Selesnya Signet

Orzhov Signet

Sol Ring

Azlask, the Swelling Scourge

Whenever Azlask, the Swelling Scourge or another colorless creature you control dies, you get an experience counter.
{W}{U}{B}{R}{G}: Creatures you control get +X/+X until end of turn, where X is the number of experience counters you have. Scions and Spawns you control gain indestructible and annihilator 1 until end of turn.