Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Exotic Orchard

{T}: Add one mana of any color that a land an opponent controls could produce.

One with the Multiverse

You may look at the top card of your library any time.
You may play lands and cast spells from the top of your library.
Once during each of your turns, you may cast a spell from your hand or the top of your library without paying its mana cost.

Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}

Call Forth the Tempest

Cascade, 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 of your library in a random order. Then do it again.)
Call Forth the Tempest deals damage to each creature your opponents control equal to the total mana value of other spells you've cast this turn.

Sunbird's Invocation

Whenever you cast a spell from your hand, reveal the top X cards of your library, where X is that spell's mana value. You may cast a spell with mana value X or less from among cards revealed this way without paying its mana cost. Put the rest on the bottom of your library in a random order.

In Garruk's Wake

Destroy all creatures you don't control and all planeswalkers you don't control.

Command Tower

Omniscience

You may cast spells from your hand without paying their mana costs.

Jodah, Archmage Eternal

Flying
You may pay {W}{U}{B}{R}{G} rather than pay the mana cost for spells you cast.

Ruinous Ultimatum

Destroy all nonland permanents your opponents control.

Imoti, Celebrant of Bounty

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.)
Spells you cast with mana value 6 or greater have cascade.

Apex Devastator

Cascade, cascade, cascade, 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. Multiple instances of cascade each trigger separately.)

Conflux

Search your library for a white card, a blue card, a black card, a red card, and a green card. Reveal those cards, put them into your hand, then shuffle.

Faeburrow Elder

Vigilance
Faeburrow Elder gets +1/+1 for each color among permanents you control.
{T}: For each color among permanents you control, add one mana of that color.

Ghalta, Stampede Tyrant

Trample
When Ghalta, Stampede Tyrant enters, put any number of creature cards from your hand onto the battlefield.

Cultivate

Search your library for up to two basic land cards, reveal those cards, put one onto the battlefield tapped and the other into your hand, then shuffle.

Fist of Suns

You may pay {W}{U}{B}{R}{G} rather than pay the mana cost for spells you cast.

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.

Chromatic Lantern

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

Sol Ring

Emergent Ultimatum

Search your library for up to three monocolored cards with different names and exile them. An opponent chooses one of those cards. Shuffle that card into your library. You may cast the other cards without paying their mana costs. Exile Emergent Ultimatum.

Genesis Ultimatum

Look at the top five cards of your library. Put any number of permanent cards from among them onto the battlefield and the rest into your hand. Exile Genesis Ultimatum.

Farseek

Search your library for a Plains, Island, Swamp, or Mountain card, put it onto the battlefield tapped, then shuffle.

Leyline Immersion

Enchant legendary creature
Enchanted creature has ward {2} and "{T}: Add five mana in any combination of colors. Spend this mana only to cast spells."