Aladdin's Lamp

{X}, {T}: The next time you would draw a card this turn, instead look at the top X cards of your library, put all but one of them on the bottom of your library in a random order, then draw a card. X can't be 0.

Abyssal Gatekeeper

When Abyssal Gatekeeper dies, each player sacrifices a creature of their choice.

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.

Ertai, the Corrupted

{U}, {T}, Sacrifice a creature or enchantment: Counter target spell.