Vito, Thorn of the Dusk Rose

Whenever you gain life, target opponent loses that much life.
{3}{B}{B}: Creatures you control gain lifelink until end of turn.

Peer into the Abyss

Target player draws cards equal to half the number of cards in their library and loses half their life. Round up each time.

Target player draws X cards and loses X life.

Deathtouch
Whenever you draw a card, you gain 2 life.
Whenever an opponent draws a card, they lose 2 life.

At the beginning of each player's upkeep, that player loses 2 life and draws two cards.

Each player discards all the cards in their hand, then draws that many cards minus one.

Target player draws two cards and loses 2 life.

Whenever an opponent draws a card, Ob Nixilis deals 1 damage to that player.
−2: Destroy target creature. Its controller draws two cards.

Flying
At the beginning of your upkeep, each opponent draws a card.

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

Whenever an opponent draws a card, this creature deals 1 damage to that player.

Whenever you gain life, target opponent loses that much life.

Whenever an opponent draws a card, this enchantment deals 1 damage to that player.