Smallpox

Each player loses 1 life, discards a card, sacrifices a creature, then sacrifices a land.

Howling Mine

At the beginning of each player's draw step, if Howling Mine is untapped, that player draws an additional card.

Winter Orb

As long as Winter Orb is untapped, players can't untap more than one land during their untap steps.

Fellwar Stone

{T}: Add one mana of any color that a land an opponent controls could produce.

Underground River

{T}: Add {C}.
{T}: Add {U} or {B}. Underground River deals 1 damage to you.

Sudden Edict

Split second (As long as this spell is on the stack, players can't cast spells or activate abilities that aren't mana abilities.)
Target player sacrifices a creature.

Baleful Strix

Flying, deathtouch
When Baleful Strix enters, draw a card.

Black Vise

As Black Vise enters, choose an opponent.
At the beginning of the chosen player's upkeep, Black Vise deals X damage to that player, where X is the number of cards in their hand minus 4.