Steam Vents

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

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Basking Rootwalla

{1}{G}: Basking Rootwalla gets +2/+2 until end of turn. Activate only once each turn.
Madness {0} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Blazing Rootwalla

{R}: Blazing Rootwalla gets +2/+0 until end of turn. Activate only once each turn.
Madness {0} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

The Underworld Cookbook

{T}, Discard a card: Create a Food token. (It's an artifact with "{2}, {T}, Sacrifice this artifact: You gain 3 life.")
{4}, {T}, Sacrifice The Underworld Cookbook: Return target creature card from your graveyard to your hand.

Ovalchase Daredevil

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

Street Wraith

Swampwalk (This creature can't be blocked as long as defending player controls a Swamp.)
Cycling—Pay 2 life. (Pay 2 life, Discard this card: Draw a card.)

Asmoranomardicadaistinaculdacar

As long as you've discarded a card this turn, you may pay {B/R} to cast this spell.
When Asmoranomardicadaistinaculdacar enters, 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.

Vengevine

Haste
Whenever you cast a spell, if it's the second creature spell you cast this turn, you may return Vengevine from your graveyard to the battlefield.

Bazaar Trademage

Flying
When Bazaar Trademage enters, draw two cards, then discard three cards.

Hollow One

This spell costs {2} less to cast for each card you've cycled or discarded this turn.
Cycling {2} ({2}, Discard this card: Draw a card.)