Niv-Mizzet Reborn

Flying
When Niv-Mizzet Reborn enters the battlefield, reveal the top ten cards of your library. For each color pair, choose a card that's exactly those colors from among them. Put the chosen cards into your hand and the rest on the bottom of your library in a random order.

Dragon Arch

{2}, {T}: You may put a multicolored creature card from your hand onto the battlefield.

Rampaging Monument

Trample
Rampaging Monument enters the battlefield with three +1/+1 counters on it.
Whenever you cast a multicolored spell, put a +1/+1 counter on Rampaging Monument.

Knight of New Alara

Each other multicolored creature you control gets +1/+1 for each of its colors.

Crystalline Crawler

Converge — Crystalline Crawler enters the battlefield with a +1/+1 counter on it for each color of mana spent to cast it.
Remove a +1/+1 counter from Crystalline Crawler: Add one mana of any color.
{T}: Put a +1/+1 counter on Crystalline Crawler.

Pyroconvergence

Whenever you cast a multicolored spell, Pyroconvergence deals 2 damage to any target.

Cascading Cataracts

Indestructible
{T}: Add {C}.
{5}, {T}: Add five mana in any combination of colors.

Bloom Tender

{T}: For each color among permanents you control, add one mana of that color.

Chromatic Orrery

You may spend mana as though it were mana of any color.
{T}: Add {C}{C}{C}{C}{C}.
{5}, {T}: Draw a card for each color among permanents you control.

Vivid Revival

Return up to three target multicolored cards from your graveyard to your hand. Exile Vivid Revival.

Prism Array

Converge — Prism Array enters the battlefield with a crystal counter on it for each color of mana spent to cast it.
Remove a crystal counter from Prism Array: Tap target creature.
{W}{U}{B}{R}{G}: Scry 3. (Look at the top three cards of your library, then put any number of them on the bottom of your library and the rest on top in any order.)

Maze Behemoth

Trample
Multicolored creatures you control have trample.

All Suns' Dawn

For each color, return up to one target card of that color from your graveyard to your hand. Exile All Suns' Dawn.

Woodland Wanderer

Vigilance, trample
Converge — Woodland Wanderer enters the battlefield with a +1/+1 counter on it for each color of mana spent to cast it.

Tome of the Guildpact

Whenever you cast a multicolored spell, draw a card.
{T}: Add one mana of any color.

Soul of Ravnica

Flying
{5}{U}{U}: Draw a card for each color among permanents you control.
{5}{U}{U}, Exile Soul of Ravnica from your graveyard: Draw a card for each color among permanents you control.

Reborn Hope

Return target multicolored card from your graveyard to your hand.

Rienne, Angel of Rebirth

Flying
Other multicolored creatures you control get +1/+0.
Whenever another multicolored creature you control dies, return it to its owner's hand at the beginning of the next end step.

Verdant Eidolon

{G}, Sacrifice Verdant Eidolon: Add three mana of any one color.
Whenever you cast a multicolored spell, you may return Verdant Eidolon from your graveyard to your hand.

Glass of the Guildpact

Multicolored creatures you control get +1/+1.

General Ferrous Rokiric

Hexproof from monocolored
Whenever you cast a multicolored spell, create a 4/4 red and white Golem artifact creature token.

Maze Glider

Flying
Multicolored creatures you control have flying.

Maze Abomination

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
Multicolored creatures you control have deathtouch.

Urza's Filter

Multicolored spells cost up to {2} less to cast.

Conqueror's Flail

Equipped creature gets +1/+1 for each color among permanents you control.
As long as Conqueror's Flail is attached to a creature, your opponents can't cast spells during your turn.
Equip {2}

Maze Sentinel

Vigilance
Multicolored creatures you control have vigilance.

Pillar of the Paruns

{T}: Add one mana of any color. Spend this mana only to cast a multicolored spell.

Bring to Light

Converge — Search your library for a creature, instant, or sorcery card with mana value less than or equal to the number of colors of mana spent to cast this spell, exile that card, then shuffle. You may cast that card without paying its mana cost.

Hero of Precinct One

Whenever you cast a multicolored spell, create a 1/1 white Human creature token.

Faeburrow Elder

Vigilance
Faeburrow Elder gets +1/+1 for each color among permanents you control.
{T}: For each color among permanents you control, add one mana of that color.