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

Barad-dûr enters the battlefield tapped unless you control a legendary creature.

{T}: Add {B}.

{X}{X}{B}, {T}: Amass Orcs X. Activate only if a creature died this turn.

({T}: Add {B} or {R}.)

As Blood Crypt enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

Bojuka Bog enters the battlefield tapped.

When Bojuka Bog enters the battlefield, exile target player's graveyard.

{T}: Add {B}.

Boseiju, Who Shelters All enters the battlefield tapped.

{T}, Pay 2 life: Add {C}. If that mana is spent on an instant or sorcery spell, that spell can't be countered.

{2}, {T}: Add {B} for each Swamp you control.

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

As an additional cost to cast this spell, sacrifice a creature.

Fling deals damage equal to the sacrificed creature's power to any target.

{T}: Add {U}.

{U}, {T}: Untap target legendary permanent.

{T}: Add {C}.

{2}, {T}: Choose a color. Add an amount of mana of that color equal to your devotion to that color. (Your devotion to a color is the number of mana symbols of that color in the mana costs of permanents you control.)

{T}: Add {C}.

{T}, Sacrifice a creature: Add {B}{B}.

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

({T}: Add {B} or {R}.)

Raucous Theater enters the battlefield tapped.

When Raucous Theater enters the battlefield, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

{T}: Add {C}.

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

Ward--Sacrifice a legendary artifact or legendary creature.

Whenever an opponent casts a spell, amass Orcs 1.

Whenever an Army you control deals combat damage to a player, the Ring tempts you.

Whenever the Ring tempts you, you may discard your hand. If you do, draw four cards.

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

({T}: Add {U} or {R}.)

As Steam Vents enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

As The Black Gate enters the battlefield, you may pay 3 life. If you don't, it enters the battlefield tapped.

{T}: Add {B}.

{1}{B}, {T}: Choose a player with the most life or tied for most life. Target creature can't be blocked by creatures that player controls this turn.

({T}: Add {U} or {R}.)

Thundering Falls enters the battlefield tapped.

When Thundering Falls enters the battlefield, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

({T}: Add {U} or {B}.)

Undercity Sewers enters the battlefield tapped.

When Undercity Sewers enters the battlefield, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Each land is a Swamp in addition to its other land types.

(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.

({T}: Add {U} or {B}.)

As Watery Grave enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.