Cadaverous Bloom

Exile a card from your hand: Add {B}{B} or {G}{G}.

Death Pits of Rath

Whenever a creature is dealt damage, destroy it. It can't be regenerated.

Seedborn Muse

Untap all permanents you control during each other player's untap step.

Season of the Witch

At the beginning of your upkeep, sacrifice Season of the Witch unless you pay 2 life.
At the beginning of the end step, destroy all untapped creatures that didn't attack this turn, except for creatures that couldn't attack.

Constant Mists

Buyback—Sacrifice a land. (You may sacrifice a land in addition to any other costs as you cast this spell. If you do, put this card into your hand as it resolves.)
Prevent all combat damage that would be dealt this turn.

Demonic Tutor

Search your library for a card, put that card into your hand, then shuffle.

Caltrops

Whenever a creature attacks, Caltrops deals 1 damage to it.

Necropotence

Skip your draw step.
Whenever you discard a card, exile that card from your graveyard.
Pay 1 life: Exile the top card of your library face down. Put that card into your hand at the beginning of your next end step.

Vampiric Tutor

Search your library for a card, then shuffle and put that card on top. You lose 2 life.

Moment's Peace

Prevent all combat damage that would be dealt this turn.
Flashback {2}{G} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Spiritmonger

Whenever Spiritmonger deals damage to a creature, put a +1/+1 counter on Spiritmonger.
{B}: Regenerate Spiritmonger.
{G}: Spiritmonger becomes the color of your choice until end of turn.

Pestilence

At the beginning of the end step, if no creatures are on the battlefield, sacrifice Pestilence.
{B}: Pestilence deals 1 damage to each creature and each player.

Vhati il-Dal

{T}: Until end of turn, target creature has base power 1 or base toughness 1.

Silvos, Rogue Elemental

Trample
{G}: Regenerate Silvos, Rogue Elemental.

Squandered Resources

Sacrifice a land: Add one mana of any type the sacrificed land could produce.

Regeneration

Enchant creature (Target a creature as you cast this. This card enters attached to that creature.)
{G}: Regenerate enchanted creature. (The next time that creature would be destroyed this turn, instead tap it, remove it from combat, and heal all damage on it.)

Festering Evil

At the beginning of your upkeep, Festering Evil deals 1 damage to each creature and each player.
{B}{B}, Sacrifice Festering Evil: It deals 3 damage to each creature and each player.