Archway Commons

This land enters tapped.
When this land enters, sacrifice it unless you pay {1}.
{T}: Add one mana of any color.

Corporeal Projection

Target creature you control gains myriad until end of turn. (Whenever it attacks, for each opponent other than defending player, you may create a token copy that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)
Overload {3}{U}{U}{R}{R} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Titania's Command

Choose two —
• Exile target player's graveyard. You gain 1 life for each card exiled this way.
• Search your library for up to two land cards, put them onto the battlefield tapped, then shuffle.
• Create two 2/2 green Bear creature tokens.
• Put two +1/+1 counters on each creature you control.

A Realm Reborn

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

Sol Ring

All-Fates Scroll

{T}: Add one mana of any color.
{7}, {T}, Sacrifice this artifact: Draw X cards, where X is the number of differently named lands you control.

Commander's Sphere

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

Aetheric Amplifier

{T}: Add one mana of any color.
{4}, {T}: Choose one. Activate only as a sorcery.
• Double the number of each kind of counter on target permanent.
• Double the number of each kind of counter you have.

Abundant Growth

Enchant land
When this Aura enters, draw a card.
Enchanted land has "{T}: Add one mana of any color."

Command Tower

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

Progenitus

Protection from everything
If Progenitus would be put into a graveyard from anywhere, reveal Progenitus and shuffle it into its owner's library instead.

Arcane Signet

Ash Barrens

{T}: Add {C}.
Basic landcycling {1} ({1}, Discard this card: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.)

Command Bridge

This land enters tapped.
When this land enters, sacrifice it unless you tap an untapped permanent you control.
{T}: Add one mana of any color.