Watermarket

: Add . Spend this mana only to cast spells with watermarks.

Split Screen

When Split Screen enters the battlefield, shuffle your library and deal it into four libraries. If anything refers to your library, choose one of your libraries for it.
Play with your libraries’ top cards revealed.
When Split Screen leaves the battlefield, shuffle your libraries together.

Secret Base

: Add .
: Add one mana of any color. Spend this mana only to cast a spell that shares a watermark with Secret Base.

Mary O’Kill

: Switch a Killbot or Mary O’Kill in your hand with one on the battlefield. (If a creature is tapped, the switched creature is tapped. The same is true for untapped, attacking, blocking, enchanted, equipped, and targeted. Any counters on a creature are on the switched creature instead.)

Dr. Julius Jumblemorph

Dr. Julius Jumblemorph is every creature type (even if this card isn’t on the battlefield).
Whenever a host enters the battlefield under your control, you may search your library and/or graveyard for a card with augment and combine it with that host. If you search your library this way, shuffle it.

Old-Fashioned Vampire

Flying
Old-Fashioned Vampire gets +2/+2 and has deathtouch as long as it’s dark outdoors.

Ranging Raptors

Enrage — Whenever Ranging Raptors is dealt damage, you may search your library for a basic land card, put it onto the battlefield tapped, then shuffle your library.

Rigging Runner

First strike
Raid — Rigging Runner enters the battlefield with a +1/+1 counter on it if you attacked this turn.

Taigam, Sidisi’s Hand

Skip your draw step.
At the beginning of your upkeep, look at the top three cards of your library. Put one of them into your hand and the rest into your graveyard.
, , Exile X cards from your graveyard: Target creature gets -X/-X until end of turn.

Taigam, Ojutai Master

Instant, sorcery, and Dragon spells you control can’t be countered.
Whenever you cast an instant or sorcery spell from your hand, if Taigam, Ojutai Master attacked this turn, that spell gains rebound. (Exile the spell as it resolves. At the beginning of your next upkeep, you may cast that card from exile without paying its mana cost.)

Uncage the Menagerie

Search your library for up to X creature cards with different names that each have converted mana cost X, reveal them, put them into your hand, then shuffle your library.

Uncage the Menagerie

Search your library for up to X creature cards with different names that each have converted mana cost X, reveal them, put them into your hand, then shuffle your library.

Hour of Devastation

All creatures lose indestructible until end of turn. Hour of Devastation deals 5 damage to each creature and each non-Bolas planeswalker.

Hour of Devastation

All creatures lose indestructible until end of turn. Hour of Devastation deals 5 damage to each creature and each non-Bolas planeswalker.

Taigam, Ojutai Master

Instant, sorcery, and Dragon spells you control can’t be countered.
Whenever you cast an instant or sorcery spell from your hand, if Taigam, Ojutai Master attacked this turn, that spell gains rebound. (Exile the spell as it resolves. At the beginning of your next upkeep, you may cast that card from exile without paying its mana cost.)

Taigam, Sidisi’s Hand

Skip your draw step.
At the beginning of your upkeep, look at the top three cards of your library. Put one of them into your hand and the rest into your graveyard.
, , Exile X cards from your graveyard: Target creature gets -X/-X until end of turn.