Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice Commander's Sphere: Draw a card.

Kodama's Reach

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.

Nature's Lore

Search your library for a Forest card, put that card onto the battlefield, then shuffle.

Cultivate

Orb of Dragonkind

{1}, {T}: Add two mana in any combination of colors. Spend this mana only to cast Dragon spells or activate abilities of Dragons.
{R}, {T}, Sacrifice Orb of Dragonkind: Look at the top seven cards of your library. You may reveal a Dragon card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

Fellwar Stone

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

Jeweled Lotus

{T}, Sacrifice Jeweled Lotus: Add three mana of any one color. Spend this mana only to cast your commander.

Ancient Tomb

{T}: Add {C}{C}. Ancient Tomb deals 2 damage to you.

Command Tower

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

Thought Vessel

You have no maximum hand size.
{T}: Add {C}.

Arcane Signet

Rampant Growth

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

Farseek

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

Chromatic Lantern

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

Sol Ring

Rogue's Passage

{T}: Add {C}.
{4}, {T}: Target creature can't be blocked this turn.

Exotic Orchard

The Ur-Dragon

Eminence — As long as The Ur-Dragon is in the command zone or on the battlefield, other Dragon spells you cast cost {1} less to cast.
Flying
Whenever one or more Dragons you control attack, draw that many cards, then you may put a permanent card from your hand onto the battlefield.