Riot Spikes

({B/R} can be paid with either {B} or {R}.)
Enchant creature
Enchanted creature gets +2/-1.

Thriving Bluff

Thriving Bluff enters tapped. As it enters, choose a color other than red.
{T}: Add {R} or one mana of the chosen color.

Psychotic Fury

Target multicolored creature gains double strike until end of turn.
Draw a card.

Thriving Moor

Thriving Moor enters tapped. As it enters, choose a color other than black.
{T}: Add {B} or one mana of the chosen color.

Island

Esper Stormblade

As long as you control another multicolored permanent, Esper Stormblade gets +1/+1 and has flying.

Maze Abomination

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

Maze Glider

Flying
Multicolored creatures you control have flying.

Thriving Isle

Thriving Isle enters tapped. As it enters, choose a color other than blue.
{T}: Add {U} or one mana of the chosen color.

Maze Rusher

Haste
Multicolored creatures you control have haste.

Sewn-Eye Drake

Jund Hackblade

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

Swamp

Clout of the Dominus

Enchant creature
As long as enchanted creature is blue, it gets +1/+1 and has shroud. (It can't be the target of spells or abilities.)
As long as enchanted creature is red, it gets +1/+1 and has haste.

Oona's Gatewarden

Defender, flying
Wither (This deals damage to creatures in the form of -1/-1 counters.)

Glamorous Outlaw

When Glamorous Outlaw enters, it deals 2 damage to each opponent and you scry 2.
{2}, Exile Glamorous Outlaw from your hand: Target land gains "{T}: Add {U}, {B}, or {R}" until Glamorous Outlaw is cast from exile. You may cast Glamorous Outlaw for as long as it remains exiled.

Mountain

Grixis Grimblade

As long as you control another multicolored permanent, Grixis Grimblade gets +1/+1 and has deathtouch. (Any amount of damage it deals to a creature is enough to destroy that creature.)