No, its not from an Un-set or Secret Lair, its from Ikoria: Lair of Behemoths
They have the option to sacrifice it to stop the damage, but that requires they spend three mana and give everyone else at the table a card
Since youre making that many Faerie Rogue tokens with flying, you can pump the tokens with rogue lords like Anowon, the Ruin Thief and Soaring Thought-Thief or cards like Gravitational Shift
Dawnglade Regent
The Universes Beyond line of cards is set to feature many more outside franchises in the future, including The Lord Of The Rings and The Walking Dead, but Warhammer is a surprisingly easy fit, since it is already filled with role-playing stats and a passionate fanbase that shouldnt have any trouble adapting to the rules of the card game
That player may search their library for a noncreature artifact card, put it onto the battlefield, then shuffle