Standard Bearer

While an opponent is choosing targets as part of casting a spell they control or activating an ability they control, that player must choose at least one Flagbearer on the battlefield if able.

Silver Wyvern

Flying
{U}: Change the target of target spell or ability that targets only this creature. The new target must be a creature.

Hydroelectric Laboratory

As this land enters, you may pay 3 life. If you don't, it enters tapped.
{T}: Add {U}.

Hydroelectric Specimen

Flash
When this creature enters, you may change the target of target instant or sorcery spell with a single target to this creature.

Hydroelectric Specimen // Hydroelectric Laboratory

Hive Mind

Whenever a player casts an instant or sorcery spell, each other player copies that spell. Each of those players may choose new targets for their copy.

Commandeer

You may exile two blue cards from your hand rather than pay this spell's mana cost.
Gain control of target noncreature spell. You may choose new targets for it. (If that spell is an artifact, enchantment, or planeswalker, the permanent enters under your control.)

Coalition Flag

Enchant creature you control
Enchanted creature is a Flagbearer.
While an opponent is choosing targets as part of casting a spell they control or activating an ability they control, that player must choose at least one Flagbearer on the battlefield if able.

Swarm Intelligence

Whenever you cast an instant or sorcery spell, you may copy that spell. You may choose new targets for the copy.

Divert

Change the target of target spell with a single target unless that spell's controller pays {2}.

Radstorm

Storm (When you cast this spell, copy it for each spell cast before it this turn.)
Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Mirari

Whenever you cast an instant or sorcery spell, you may pay {3}. If you do, copy that spell. You may choose new targets for the copy.

Twincast

Copy target instant or sorcery spell. You may choose new targets for the copy.

Perplexing Chimera

Whenever an opponent casts a spell, you may exchange control of this creature and that spell. If you do, you may choose new targets for the spell. (If the spell becomes a permanent, you control that permanent.)

Willbender

Morph {1}{U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)
When this creature is turned face up, change the target of target spell or ability with a single target.

Coalition Honor Guard

Insidious Will

Choose one —
• Counter target spell.
• You may choose new targets for target spell.
• Copy target instant or sorcery spell. You may choose new targets for the copy.

Explore the Vastlands

Each player looks at the top five cards of their library and may reveal a land card and/or an instant or sorcery card from among them. Each player puts the cards they revealed this way into their hand and the rest on the bottom of their library in a random order. Each player gains 3 life.

Wandering Archaic

Whenever an opponent casts an instant or sorcery spell, they may pay {2}. If they don't, you may copy that spell. You may choose new targets for the copy.

Wandering Archaic // Explore the Vastlands

Narset's Reversal

Copy target instant or sorcery spell, then return it to its owner's hand. You may choose new targets for the copy.

Curse of Echoes

Enchant player
Whenever enchanted player casts an instant or sorcery spell, each other player may copy that spell and may choose new targets for the copy they control.

Quicksilver Dragon

Flying
{U}: If target spell has only one target and that target is this creature, change that spell's target to another creature.
Morph {4}{U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)

Twinning Staff

If you would copy a spell one or more times, instead copy it that many times plus an additional time. You may choose new targets for the additional copy.
{7}, {T}: Copy target instant or sorcery spell you control. You may choose new targets for the copy.

Deflection

Change the target of target spell with a single target.

Meletis Charlatan

{2}{U}, {T}: The controller of target instant or sorcery spell copies it. That player may choose new targets for the copy.

Captured by the Consulate

Enchant creature you don't control
Enchanted creature can't attack.
Whenever an opponent casts a spell, if it has a single target, change the target to enchanted creature if able.

Blade of Selves

Equipped creature has myriad. (Whenever it attacks, for each opponent other than defending player, you may create a token copy that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)
Equip {4}

Tempest Technique

Storm (When you cast this spell, copy it for each spell cast before it this turn. You may choose new targets for the copies. Copies become tokens.)
Enchant creature you control
Enchanted creature gets +1/+1 for each enchantment you control.

Astral Steel

Target creature gets +1/+2 until end of turn.
Storm (When you cast this spell, copy it for each spell cast before it this turn. You may choose new targets for the copies.)

Redirect

You may choose new targets for target spell.

Mizzium Meddler

Flash (You may cast this spell any time you could cast an instant.)
When this creature enters, you may change a target of target spell or ability to this creature.

Meddle

If target spell has only one target and that target is a creature, change that spell's target to another creature.

Zethi, Arcane Blademaster

Multikicker {W/U}
When Zethi, Arcane Blademaster enters, exile up to X target instant cards from your graveyard, where X is the number of times Zethi was kicked. Put a kick counter on each of them.
Whenever Zethi attacks, copy each exiled card you own with a kick counter on it. You may cast the copies.

Misdirection

You may exile a blue card from your hand rather than pay this spell's mana cost.
Change the target of target spell with a single target.

Mirrorpool

This land enters tapped.
{T}: Add {C}.
{2}{C}, {T}, Sacrifice this land: Copy target instant or sorcery spell you control. You may choose new targets for the copy.
{4}{C}, {T}, Sacrifice this land: Create a token that's a copy of target creature you control.

Spellskite

{U/P}: Change a target of target spell or ability to this creature. ({U/P} can be paid with either {U} or 2 life.)