Pure Reflection

Whenever a player casts a creature spell, destroy all Reflections. Then that player creates an X/X white Reflection creature token, where X is the mana value of that spell.

Blood Artist

Whenever Blood Artist or another creature dies, target player loses 1 life and you gain 1 life.

Elenda, the Dusk Rose

Lifelink
Whenever another creature dies, put a +1/+1 counter on Elenda, the Dusk Rose.
When Elenda dies, create X 1/1 white Vampire creature tokens with lifelink, where X is Elenda's power.

Cordial Vampire

Whenever Cordial Vampire or another creature dies, put a +1/+1 counter on each Vampire you control.

Purgatory

Whenever a nontoken creature is put into your graveyard from the battlefield, exile that card.
At the beginning of your upkeep, you may pay {4} and 2 life. If you do, return a card exiled with Purgatory to the battlefield.