Demonic Tutor

Search your library for a card, put that card into your hand, then shuffle.

Natural Order

As an additional cost to cast this spell, sacrifice a green creature.
Search your library for a green creature card, put it onto the battlefield, then shuffle.

Omnath, Locus of Creation

When Omnath, Locus of Creation enters the battlefield, draw a card.
Landfall — Whenever a land enters the battlefield under your control, you gain 4 life if this is the first time this ability has resolved this turn. If it's the second time, add {R}{G}{W}{U}. If it's the third time, Omnath deals 4 damage to each opponent and each planeswalker you don't control.

Diabolic Tutor

Threefold Signal

When Threefold Signal enters the battlefield, scry 3.
Each spell you cast that's exactly three colors has replicate {3}. (When you cast it, copy it for each time you paid its replicate cost. You may choose new targets for the copies. A copy of a permanent spell becomes a token.)

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.

Cabal Coffers

{2}, {T}: Add {B} for each Swamp you control.

Chromatic Lantern

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

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.

Omnath, Locus of the Roil

When Omnath, Locus of the Roil enters the battlefield, it deals damage to any target equal to the number of Elementals you control.
Landfall — Whenever a land enters the battlefield under your control, put a +1/+1 counter on target Elemental you control. If you control eight or more lands, draw a card.