As Pithing Needle enters the battlefield, choose a card name. Activated abilities of sources with the chosen name can't be activated unless they're mana abilities.

{T}: Target player exiles a card from their graveyard. {1}, Exile Relic of Progenitus: Exile all graveyards. Draw a card.

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

As long as you've discarded a card this turn, you may pay {B/R} to cast this spell. When Asmoranomardicadaistinaculdacar enters the battlefield, you may search your library for a card named The Underworld Cookbook, reveal it, put it into your hand, then shuffle. Sacrifice two Foods: Target creature deals 6 damage to itself.

Whenever an artifact enters the battlefield under your control, you may return Ovalchase Daredevil from your graveyard to your hand.

When Protean Hulk dies, search your library for any number of creature cards with total mana value 6 or less, put them onto the battlefield, then shuffle.

When Rosie Cotton of South Lane enters the battlefield, create a Food token. (It's an artifact with "{2}, {T}, Sacrifice this artifact: You gain 3 life.") Whenever you create a token, put a +1/+1 counter on target creature you control other than Rosie.

({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.

{T}, Pay 1 life, Sacrifice Bloodstained Mire: Search your library for a Swamp or Mountain card, put it onto the battlefield, then shuffle.

{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.

({T}: Add {W} or {B}.) As Godless Shrine enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

({T}: Add {B} or {G}.) As Overgrown Tomb enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

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

({T}: Add {B}.)

(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}, Pay 1 life, Sacrifice Verdant Catacombs: Search your library for a Swamp or Forest card, put it onto the battlefield, then shuffle.

Return target creature card from your graveyard to the battlefield. Sacrifice that creature at the beginning of the next end step.

Return target nonlegendary creature card from your graveyard to the battlefield with a -1/-1 counter on it.

As Alpine Moon enters the battlefield, choose a nonbasic land card name. Lands your opponents control with the chosen name lose all land types and abilities, and they gain "{T}: Add one mana of any color."

{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.

Sunburst (This enters the battlefield with a charge counter on it for each color of mana spent to cast it.) {2}, Sacrifice Engineered Explosives: Destroy each nonland permanent with mana value equal to the number of charge counters on Engineered Explosives.

When Haywire Mite dies, you gain 2 life. {G}, Sacrifice Haywire Mite: Exile target noncreature artifact or noncreature enchantment.

If Leyline of the Void is in your opening hand, you may begin the game with it on the battlefield. If a card would be put into an opponent's graveyard from anywhere, exile it instead.

Changeling Whenever you cast an instant or sorcery spell, if it targets one or more other permanents you control, create a token that's a copy of one of those permanents. When a spell or ability an opponent controls causes you to discard this card, create a token that's a copy of target permanent.