The EPIC Storm relies heavily on Lion's Eye Diamond, Lotus Petal, and graveyard recursion through Echo of Eons flashback and Beseech the Mirror, so Endurance's enters-the-battlefield ability to put a target player's graveyard on the bottom of their library is a powerful disruption tool, and its evoke mode lets us cast it for free on their turn to blow up a key graveyard resource at exactly the wrong moment for them. The extra Thoughtseize helps strip a combo piece like Burning Wish or Tendrils of Agony before they can protect it with Veil of Summer. Abrupt Decay answers Hexing Squelcher or an early support artifact/creature cleanly and can't be stopped by their own protection. We cut cards that are too slow or passive against a combo deck that can kill before we stabilize.