Sky Diamond

Sky Diamond enters the battlefield tapped.
{T}: Add {U}.

Tatyova, Benthic Druid

Landfall — Whenever a land enters the battlefield under your control, you gain 1 life and draw a card.

Archelos, Lagoon Mystic

As long as Archelos, Lagoon Mystic is tapped, other permanents enter the battlefield tapped.
As long as Archelos is untapped, other permanents enter the battlefield untapped.

Arcane Signet

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

Courser of Kruphix

Play with the top card of your library revealed.
You may play lands from the top of your library.
Landfall — Whenever a land enters the battlefield under your control, you gain 1 life.

Sol Ring

Azusa, Lost but Seeking

You may play two additional lands on each of your turns.

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 of your library in a random order.)
Spells you cast with mana value 6 or greater have cascade.

Charcoal Diamond

Charcoal Diamond enters the battlefield tapped.
{T}: Add {B}.

Moss Diamond

Moss Diamond enters the battlefield tapped.
{T}: Add {G}.

Exploration

You may play an additional land on each of your turns.

Springleaf Drum

{T}, Tap an untapped creature you control: Add one mana of any color.