My Sister is the Grand Supreme

Iris and Lyra are sisters from an ordinary mage family, but Iris secretly hides that she is the legendary Grand Supreme of Stardust, with only thirty percent of her power restored after being sealed by the Lord of the Abyss. To protect Lyra from Abyssal assassins, she lives quietly among common mages, trusted only by a few loyal followers. Lyra has devoted herself to Dylan, heir of the powerful Fire House, and is eagerly awaiting their engagement party. On that day, Dylan publicly ends the betrothal, having secretly turned to Chloe, the Water House prodigy, and Chloe begins humiliating Lyra with magic until she nearly collapses.