Esiki, the Woven Prophet

Whenever Esiki attacks, exile the top four cards
of your library. Until end of turn, you may cast enchantment spells exiled this way.
Whenever the final chapter ability of a Saga
you control triggers, you may pay {u}{r}{w}. If you
do, return Esiki from your graveyard to the battlefield tapped.
"The the hero of every story, and the teller of every
tale."