Everlast, Shadow Overlord

Whenever you pay life, each opponent creates a 2/1 Nightmare creature token with haste. Then, goad all Nightmares.

Whenever one or more Nightmares deal combat damage to
a player, exile the top card of your library. You may play that card for as long as it remains exiled by paying life equal to its mana value in addition to its other costs.

{3}{b}{r}, Pay 1 life: Until your next turn, each creature is a Nightmare in addition to its other types and attacks each combat if able.