Tome of the Guildpact

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

Joiner Adept

Lands you control have "{T}: Add one mana of any color."

Plains

Island

Brute Strength

Target creature gets +3/+1 and gains trample until end of turn.

Knight of New Alara

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

Dune-Brood Nephilim

Whenever Dune-Brood Nephilim deals combat damage to a player, create a 1/1 colorless Sand creature token for each land you control.

Yore-Tiller Nephilim

Whenever Yore-Tiller Nephilim attacks, return target creature card from your graveyard to the battlefield tapped and attacking.

Witch-Maw Nephilim

Whenever you cast a spell, you may put two +1/+1 counters on Witch-Maw Nephilim.
Whenever Witch-Maw Nephilim attacks, it gains trample until end of turn if its power is 10 or greater.

Mountain

Might of the Nephilim

Target creature gets +2/+2 until end of turn for each of its colors.

Rampant Growth

Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Channel the Suns

Forest

Ink-Treader Nephilim

Whenever a player casts an instant or sorcery spell, if that spell targets only Ink-Treader Nephilim, copy the spell for each other creature that spell could target. Each copy targets a different one of those creatures.

Swamp

Glint-Eye Nephilim

Whenever Glint-Eye Nephilim deals combat damage to a player, draw that many cards.
{1}, Discard a card: Glint-Eye Nephilim gets +1/+1 until end of turn.

Blessing of the Nephilim

Enchant creature
Enchanted creature gets +1/+1 for each of its colors.

Omnath, Locus of All

If you would lose unspent mana, that mana becomes black instead.
At the beginning of your precombat main phase, look at the top card of your library. You may reveal that card if it has three or more colored mana symbols in its mana cost. If you do, add three mana in any combination of its colors and put it into your hand. If you don't reveal it, put it into your hand.