Gloryscale Viashino

Whenever you cast a multicolored spell, Gloryscale Viashino gets +3/+3 until end of turn.

Marisi's Twinclaws

Giant Ambush Beetle

Haste
When Giant Ambush Beetle enters, you may have target creature block it this turn if able.

Naya Hushblade

As long as you control another multicolored permanent, Naya Hushblade gets +1/+1 and has shroud. (It can't be the target of spells or abilities.)

Bloodbraid Elf

Haste (This creature can attack and {T} as soon as it comes under your control.)
Cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order.)

Jund Hackblade

As long as you control another multicolored permanent, Jund Hackblade gets +1/+1 and has haste.

Knight of New Alara

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

Blitz Hellion

Trample, haste
At the beginning of the end step, Blitz Hellion's owner shuffles it into their library.

Enlisted Wurm

Cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order.)

Trace of Abundance

Enchant land
Enchanted land has shroud. (It can't be the target of spells or abilities.)
Whenever enchanted land is tapped for mana, its controller adds an additional one mana of any color.

Bant Sureblade

As long as you control another multicolored permanent, Bant Sureblade gets +1/+1 and has first strike.

Violent Outburst

Cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order.)
Creatures you control get +1/+0 until end of turn.