March of Swirling Mist

As an additional cost to cast this spell, you may exile any number of blue cards from your hand. This spell costs {2} less to cast for each card exiled this way.
Up to X target creatures phase out. (While they're phased out, they're treated as though they don't exist. Each one phases in before its controller untaps during their next untap step.)

Livaan, Cultist of Tiamat

Whenever you cast a noncreature spell, target creature gets +X/+0 until end of turn, where X is that spell's mana value.
Choose a Background (You can have a Background as a second commander.)

Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}

Archaeomancer

When Archaeomancer enters the battlefield, return target instant or sorcery card from your graveyard to your hand.

Elminster's Simulacrum

For each opponent, you create a token that's a copy of up to one target creature that player controls.

Radiant Scrollwielder

Instant and sorcery spells you control have lifelink.
At the beginning of your upkeep, exile an instant or sorcery card at random from your graveyard. You may cast it this turn. If a spell cast this way would be put into your graveyard, exile it instead.

Icy Blast

Tap X target creatures.
Ferocious — If you control a creature with power 4 or greater, those creatures don't untap during their controllers' next untap steps.

Magma Opus

Magma Opus deals 4 damage divided as you choose among any number of targets. Tap two target permanents. Create a 4/4 blue and red Elemental creature token. Draw two cards.
{U/R}{U/R}, Discard Magma Opus: Create a Treasure token.

Pull from the Deep

Return up to one target instant card and up to one target sorcery card from your graveyard to your hand. Exile Pull from the Deep.

Erratic Cyclops

Trample
Whenever you cast an instant or sorcery spell, Erratic Cyclops gets +X/+0 until end of turn, where X is that spell's mana value.

Negate

Willbreaker

Whenever a creature an opponent controls becomes the target of a spell or ability you control, gain control of that creature for as long as you control Willbreaker.

Hinata, Dawn-Crowned

Flying, trample
Spells you cast cost {1} less to cast for each target.
Spells your opponents cast cost {1} more to cast for each target.

Zaffai, Thunder Conductor

Magecraft — Whenever you cast or copy an instant or sorcery spell, scry 1. If that spell's mana value is 5 or greater, create a 4/4 blue and red Elemental creature token. If that spell's mana value is 10 or greater, Zaffai, Thunder Conductor deals 10 damage to an opponent chosen at random.

Aurelia's Fury

Aurelia's Fury deals X damage divided as you choose among any number of targets. Tap each creature dealt damage this way. Players dealt damage this way can't cast noncreature spells this turn.

Heliod's Intervention

Choose one —
• Destroy X target artifacts and/or enchantments.
• Target player gains twice X life.

Crackle with Power

Crackle with Power deals five times X damage to each of up to X targets.

Ardent Elementalist

When Ardent Elementalist enters the battlefield, return target instant or sorcery card from your graveyard to your hand.

Arcane Denial

Counter target spell. Its controller may draw up to two cards at the beginning of the next turn's upkeep.
You draw a card at the beginning of the next turn's upkeep.

Distorting Wake

Return X target nonland permanents to their owners' hands.

Soulfire Grand Master

Lifelink
Instant and sorcery spells you control have lifelink.
{2}{U/R}{U/R}: The next time you cast an instant or sorcery spell from your hand this turn, put that card into your hand instead of into your graveyard as it resolves.

Baral's Expertise

Return up to three target artifacts and/or creatures to their owners' hands.
You may cast a spell with mana value 4 or less from your hand without paying its mana cost.

Wizards of Thay

Myriad (Whenever this creature attacks, for each opponent other than defending player, you may create a token that's a copy of this creature that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)
Instant and sorcery spells you cast cost {1} less to cast.
You may cast sorcery spells as though they had flash.

Semester's End

Exile any number of target creatures and/or planeswalkers you control. At the beginning of the next end step, return each of them to the battlefield under its owner's control. Each of them enters the battlefield with an additional +1/+1 counter on it if it's a creature and an additional loyalty counter on it if it's a planeswalker.

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

Feather, the Redeemed

Flying
Whenever you cast an instant or sorcery spell that targets a creature you control, exile that card instead of putting it into your graveyard as it resolves. If you do, return it to your hand at the beginning of the next end step.

By Force

Decoy Gambit

For each opponent, choose up to one target creature that player controls, then return that creature to its owner's hand unless its controller has you draw a card.

Curse of the Swine

Exile X target creatures. For each creature exiled this way, its controller creates a 2/2 green Boar creature token.

Comet Storm

Multikicker {1} (You may pay an additional {1} any number of times as you cast this spell.)
Choose any target, then choose another target for each time this spell was kicked. Comet Storm deals X damage to each of them.

Disorder in the Court

Exile X target creatures, then investigate X times. Return the exiled cards to the battlefield tapped under their owners' control at the beginning of the next end step. (To investigate, create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Whirlwind of Thought

Whenever you cast a noncreature spell, draw a card.

Mystic Confluence

Choose three. You may choose the same mode more than once.
• Counter target spell unless its controller pays {3}.
• Return target creature to its owner's hand.
• Draw a card.

Crush Contraband

Choose one or both —
• Exile target artifact.
• Exile target enchantment.

Goblin Electromancer

Instant and sorcery spells you cast cost {1} less to cast.

Storm-Kiln Artist

Storm-Kiln Artist gets +1/+0 for each artifact you control.
Magecraft — Whenever you cast or copy an instant or sorcery spell, create a Treasure token.