Blade Juggler

Spectacle {2}{B} (You may cast this spell for its spectacle cost rather than its mana cost if an opponent lost life this turn.)
When Blade Juggler enters the battlefield, it deals 1 damage to you and you draw a card.

Savage Gorger

Flying
At the beginning of your end step, if an opponent lost life this turn, put a +1/+1 counter on Savage Gorger. (Damage causes loss of life.)

Famished Foragers

When Famished Foragers enters the battlefield, if an opponent lost life this turn, add {R}{R}{R}.
{2}{R}, Discard a card: Draw a card.

Chain Lightning

Chain Lightning deals 3 damage to any target. Then that player or that permanent's controller may pay {R}{R}. If the player does, they may copy this spell and may choose a new target for that copy.

Bat Whisperer

When Bat Whisperer enters the battlefield, if an opponent lost life this turn, create a 1/1 black Bat creature token with flying.

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Arrogant Outlaw

When Arrogant Outlaw enters the battlefield, if an opponent lost life this turn, each opponent loses 2 life and you gain 2 life.

Mounted Dreadknight

Trample
Mounted Dreadknight enters the battlefield with a +1/+1 counter on it if an opponent lost life this turn.

Jagged Barrens

Jagged Barrens enters the battlefield tapped.
When Jagged Barrens enters the battlefield, it deals 1 damage to target opponent.
{T}: Add {B} or {R}.

Skewer the Critics

Spectacle {R} (You may cast this spell for its spectacle cost rather than its mana cost if an opponent lost life this turn.)
Skewer the Critics deals 3 damage to any target.