Nasuya, Sworn to Oni

When Nasuya enters the battlefield, each player
puts the top six cards of their library into their
graveyard.
{6}{u/r}{u/r}: Choose a random instant or sorcery spell
in target player's graveyard, copy it twice. Until
the end of your next turn, you may cast these
copies as though they had flash and without
paying their mana costs.