Syncopate

Counter target spell unless its controller pays {X}. If that spell is countered this way, exile it instead of putting it into its owner's graveyard.

Swamp

Persuasion

Enchant creature (Target a creature as you cast this. This card enters attached to that creature.)
You control enchanted creature.

Concentrate

Cephalid Looter

{T}: Target player draws a card, then discards a card.

Dirty Wererat

{B}, Discard a card: Regenerate Dirty Wererat.
Threshold — As long as seven or more cards are in your graveyard, Dirty Wererat gets +2/+2 and can't block.

Shadowmage Infiltrator

Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)
Whenever Shadowmage Infiltrator deals combat damage to a player, you may draw a card.

Ghastly Demise

Destroy target nonblack creature if its toughness is less than or equal to the number of cards in your graveyard.

Amugaba

Flying
{2}{U}, Discard a card: Return Amugaba to its owner's hand.

Careful Study

Innocent Blood

Each player sacrifices a creature of their choice.

Skull Fracture

Target player discards a card.
Flashback {3}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Psychatog

Discard a card: Psychatog gets +1/+1 until end of turn.
Exile two cards from your graveyard: Psychatog gets +1/+1 until end of turn.

Mind Burst

Target player discards X cards, where X is one plus the number of cards named Mind Burst in all graveyards.

Childhood Horror

Flying
Threshold — As long as seven or more cards are in your graveyard, Childhood Horror gets +2/+2 and can't block.