Night Market Lookout

Whenever this creature becomes tapped, each opponent loses 1 life and you gain 1 life.

Mardu Shadowspear

Whenever this creature attacks, each opponent loses 1 life.
Dash {1}{B} (You may cast this spell for its dash cost. If you do, it gains haste, and it's returned from the battlefield to its owner's hand at the beginning of the next end step.)

Pulse Tracker

Whenever this creature attacks, each opponent loses 1 life.

Thornbow Archer

Whenever this creature attacks, each opponent who doesn't control an Elf loses 1 life.

Sanctum of Stone Fangs

At the beginning of your first main phase, each opponent loses X life and you gain X life, where X is the number of Shrines you control.

Vicious Conquistador

Belbe, Corrupted Observer

At the beginning of each postcombat main phase, the active player adds {C}{C} for each of your opponents who lost life this turn. (Damage causes loss of life.)