Rejuvenating Springs

Rejuvenating Springs enters tapped unless you have two or more opponents.
{T}: Add {G} or {U}.

Stomping Ground

({T}: Add {R} or {G}.)
As Stomping Ground enters, you may pay 2 life. If you don't, it enters tapped.

Ketria Triome

({T}: Add {G}, {U}, or {R}.)
Ketria Triome enters tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)

Slagwoods Bridge

Slagwoods Bridge enters tapped.
Indestructible
{T}: Add {R} or {G}.

Treasure Vault

{T}: Add {C}.
{X}{X}, {T}, Sacrifice Treasure Vault: Create X Treasure tokens.

Command Tower

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

Darksteel Citadel

Breeding Pool

({T}: Add {G} or {U}.)
As Breeding Pool enters, you may pay 2 life. If you don't, it enters tapped.

Tree of Tales

Tanglepool Bridge

Tanglepool Bridge enters tapped.
Indestructible
{T}: Add {G} or {U}.

Silverbluff Bridge

Silverbluff Bridge enters tapped.
Indestructible
{T}: Add {U} or {R}.

Mountain

Exotic Orchard

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

Forest

Seat of the Synod

Scalding Tarn

{T}, Pay 1 life, Sacrifice Scalding Tarn: Search your library for an Island or Mountain card, put it onto the battlefield, then shuffle.

Urza's Saga

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Urza's Saga gains "{T}: Add {C}."
II — Urza's Saga gains "{2}, {T}: Create a 0/0 colorless Construct artifact creature token with 'This creature gets +1/+1 for each artifact you control.'"
III — Search your library for an artifact card with mana cost {0} or {1}, put it onto the battlefield, then shuffle.

Rashmi and Ragavan

Whenever you cast your first spell during each of your turns, exile the top card of target opponent's library and create a Treasure token. Then you may cast the exiled card without paying its mana cost if it's a spell with mana value less than the number of artifacts you control. If you don't cast it this way, you may cast it this turn.

Boseiju, Who Endures

{T}: Add {G}.
Channel — {1}{G}, Discard Boseiju, Who Endures: Destroy target artifact, enchantment, or nonbasic land an opponent controls. That player may search their library for a land card with a basic land type, put it onto the battlefield, then shuffle. This ability costs {1} less to activate for each legendary creature you control.

Island

Training Center

Training Center enters tapped unless you have two or more opponents.
{T}: Add {U} or {R}.

Great Furnace

Frontier Bivouac

Frontier Bivouac enters tapped.
{T}: Add {G}, {U}, or {R}.

Schema Thief

Flying
Whenever Schema Thief deals combat damage to a player, create a token that's a copy of target artifact that player controls.

Steam Vents

({T}: Add {U} or {R}.)
As Steam Vents enters, you may pay 2 life. If you don't, it enters tapped.