Evelynn, The Covetous

Flash
Whenever Evelynn, the Covetous or another
Vampire enters the battlefield under your
control, exile the top card of each player's library
with a collection counter on it.
Once each turn, you may play a card from exile
with a collection counter on it if it was exiled by
an ability you controlled, and you may spend
mana as though it were any colour to cast it.