Serum Powder

{T}: Add {C}.
Any time you could mulligan and this card is in your hand, you may exile all the cards from your hand, then draw that many cards. (You can do this in addition to taking mulligans.)

Go for the Throat

Heartless Summoning

Creature spells you cast cost {2} less to cast.
Creatures you control get -1/-1.

Archive Trap

If an opponent searched their library this turn, you may pay {0} rather than pay this spell's mana cost.
Target opponent mills thirteen cards.

The Sibsig Ceremony

Creature spells you cast cost {2} less to cast.
Whenever a creature you control enters, if you cast it, destroy that creature, then create a 2/2 black Zombie Druid creature token.

Galvanic Discharge

Choose target creature or planeswalker. You get {E}{E}{E} (three energy counters), then you may pay any amount of {E}. Galvanic Discharge deals that much damage to that permanent.

Blood Crypt

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

Imperial Recruiter

When this creature enters, search your library for a creature card with power 2 or less, reveal it, put it into your hand, then shuffle.

Swamp

Strike It Rich

Create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")
Flashback {2}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Mountain

Grapeshot

Grapeshot deals 1 damage to any target.
Storm (When you cast this spell, copy it for each spell cast before it this turn. You may choose new targets for the copies.)

Bloodstained Mire

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

Impact Tremors

Whenever a creature you control enters, this enchantment deals 1 damage to each opponent.

Faithless Looting

Draw two cards, then discard two cards.
Flashback {2}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Searstep Pathway

Blightstep Pathway

Blightstep Pathway // Searstep Pathway

Thoughtseize

Target player reveals their hand. You choose a nonland card from it. That player discards that card. You lose 2 life.

Pithing Needle

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

Fatal Push

Destroy target creature if it has mana value 2 or less.
Revolt — Destroy that creature if it has mana value 4 or less instead if a permanent left the battlefield under your control this turn.

Goblin Bombardment

Sacrifice a creature: This enchantment deals 1 damage to any target.

Myr Retriever

When this creature dies, return another target artifact card from your graveyard to your hand.