Flux Channeler

Whenever you cast a noncreature spell, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Sol Ring

Aqueous Form

Enchant creature
Enchanted creature can't be blocked.
Whenever enchanted creature attacks, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Aetherize

Return all attacking creatures to their owner's hand.

Arcane Signet

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

Four Knocks

Vanishing 4 (This enchantment enters with four time counters on it. At the beginning of your upkeep, remove a time counter from it. When the last is removed, sacrifice it.)
At the beginning of your first main phase, draw a card.

Grateful Apparition

Flying
Whenever this creature deals combat damage to a player or planeswalker, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Azorius Signet

Norn's Choirmaster

Flying, first strike
Whenever a commander you control enters or attacks, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Command Tower

Spirit Mantle

Enchant creature
Enchanted creature gets +1/+1 and has protection from creatures.

Path to Exile

Exile target creature. Its controller may search their library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Wibbly-wobbly, Timey-wimey

Time travel. (For each suspended card you own and each permanent you control with a time counter on it, you may add or remove a time counter.)
Draw a card.

Deepglow Skate

When this creature enters, double the number of each kind of counter on any number of target permanents.

All of History, All at Once

Time travel. (For each suspended card you own and each permanent you control with a time counter on it, you may add or remove a time counter.)
Storm (When you cast this spell, copy it for each spell cast before it this turn.)

Zinnia, Valley's Voice

Flying
Zinnia gets +X/+0, where X is the number of other creatures you control with base power 1.
Creature spells you cast have offspring {2}. (You may pay an additional {2} as you cast a creature spell. If you do, when that creature enters, create a 1/1 token copy of it.)

Thrummingbird

Flying
Whenever this creature deals combat damage to a player, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Time Beetle

Skulk (This creature can't be blocked by creatures with greater power.)
Parallel Universe — Whenever this creature deals combat damage to a player, time travel. (For each suspended card you own and each permanent you control with a time counter on it, you may add or remove a time counter.)

Boros Signet

Lightning Greaves

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

Rapid Hybridization

Destroy target creature. It can't be regenerated. That creature's controller creates a 3/3 green Frog Lizard creature token.

Sword Coast Sailor

Commander creatures you own have "Whenever this creature attacks a player, if no opponent has more life than that player, this creature can't be blocked this turn."

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice this artifact: Draw a card.

Urza's Ruinous Blast

(You may cast a legendary sorcery only if you control a legendary creature or planeswalker.)
Exile all nonland permanents that aren't legendary.

Fellwar Stone

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

Flaming Fist

Commander creatures you own have "Whenever this creature attacks, it gains double strike until end of turn."

Flawless Maneuver

If you control a commander, you may cast this spell without paying its mana cost.
Creatures you control gain indestructible until end of turn.

Faithless Looting

Draw two cards, then discard two cards.
Flashback {2}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Izzet Signet

Cut a Deal

Each opponent draws a card, then you draw a card for each opponent who drew a card this way.

Fractured Identity

Exile target nonland permanent. Each player other than its controller creates a token that's a copy of it.