When Covetous Castaway dies, mill three cards. (Put the top three cards of your library into your graveyard.)

Disturb (You may cast this card from your graveyard transformed for its disturb cost.)

Each player chooses up to two creatures they control, then sacrifices the rest. Then you create a tapped Treasure token for each creature your opponents control.

Target opponent reveals their hand. You choose a nonland card from that player's graveyard or hand and exile it. You may cast that card for as long as it remains exiled, and you may spend mana as though it were mana of any color to cast that spell.

Flash

Whenever Evelyn, 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 mana of any color to cast it.