Imprint — When Isochron Scepter enters the battlefield, you may exile an instant card with mana value 2 or less from your hand. {2}, {T}: You may copy the exiled card. If you do, you may cast the copy without paying its mana cost.

Whenever you cast a noncreature spell, surveil 1. (Look at the top card of your library. You may put that card into your graveyard.) Delirium — As long as there are four or more card types among cards in your graveyard, Dragon's Rage Channeler gets +2/+2, has flying, and attacks each combat if able.

Instant and sorcery spells you cast cost {1} less to cast.

Mutate {U/R}{U/R} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.) Whenever this creature mutates, return target instant or sorcery card from your graveyard to your hand.

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.) Flying Murktide Regent enters the battlefield with a +1/+1 counter on it for each instant and sorcery card exiled with it. Whenever an instant or sorcery card leaves your graveyard, put a +1/+1 counter on Murktide Regent.

Choose one — • Counter target artifact or enchantment spell. If a spell is countered this way, exile it instead of putting it into its owner's graveyard. • Counter target activated or triggered ability.

Counter target spell, activated ability, or triggered ability. (Mana abilities can't be targeted.)

Counter target activated ability, triggered ability, or legendary spell.

({T}: Add {U}.)

({T}: Add {R}.)

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

Spirebluff Canal enters the battlefield tapped unless you control two or fewer other lands. {T}: Add {U} or {R}.

Look at the top three cards of your library. Put one of them into your hand, put one of them on the bottom of your library, and exile one of them. You may play the exiled card this turn.

Amass Zombies X, where X is the number of instant and sorcery cards in your graveyard. (Put X +1/+1 counters on an Army you control. It's also a Zombie. If you don't control an Army, create a 0/0 black Zombie Army creature token first.)

Nonbasic lands are Mountains.

Counter target spell.

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.

Flying Whenever you cast an instant or sorcery spell, creatures you control get +1/+0 and gain trample until end of turn.

{2}, {T}: Copy target activated or triggered ability you control. You may choose new targets for the copy. {3}, {T}: Copy target instant or sorcery spell you control. You may choose new targets for the copy. {4}, {T}: Copy target permanent spell you control. (The copy becomes a token.)

Flying Instant and sorcery spells you cast cost {1} less to cast.

Flash When Tishana's Tidebinder enters the battlefield, counter up to one target activated or triggered ability. If an ability of an artifact, creature, or planeswalker is countered this way, that permanent loses all abilities for as long as Tishana's Tidebinder remains on the battlefield. (Mana abilities can't be targeted.)

(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.