Chromanticore

Bestow {2}{W}{U}{B}{R}{G} (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached to a creature.)
Flying, first strike, vigilance, trample, lifelink
Enchanted creature gets +4/+4 and has flying, first strike, vigilance, trample, and lifelink.

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.)

Mountain

Bant Sureblade

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

Expressive Iteration

Look at the top three cards of your library. Put one of them into your hand, put one of them on the bottom of your library, and exile one of them. You may play the exiled card this turn.

Fusion Elemental

Evolving Wilds

{T}, Sacrifice Evolving Wilds: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Renegade Map

Renegade Map enters tapped.
{T}, Sacrifice Renegade Map: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.

Forest

Paragon of the Amesha

First strike
{W}{U}{B}{R}{G}: Until end of turn, Paragon of the Amesha becomes an Angel, gets +3/+3, and gains flying and lifelink.

Deathsprout

Destroy target creature. Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Dragonsoul Knight

First strike
{W}{U}{B}{R}{G}: Until end of turn, Dragonsoul Knight becomes a Dragon, gets +5/+3, and gains flying and trample.

Who // What // When // Where // Why

Terramorphic Expanse

{T}, Sacrifice Terramorphic Expanse: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Swamp

Island

Staggering Insight

Enchant creature
Enchanted creature gets +1/+1 and has lifelink and "Whenever this creature deals combat damage to a player, draw a card."

Plains

Draco

Domain — This spell costs {2} less to cast for each basic land type among lands you control.
Flying
Domain — At the beginning of your upkeep, sacrifice Draco unless you pay {10}. This cost is reduced by {2} for each basic land type among lands you control.

Tribal Flames

Domain — Tribal Flames deals X damage to any target, where X is the number of basic land types among lands you control.

Dack's Duplicate

You may have Dack's Duplicate enter as a copy of any creature on the battlefield, except it has haste and dethrone. (Whenever it attacks the player with the most life or tied for most life, put a +1/+1 counter on it.)