My Sister is the Grand Supreme

Iris and Lyra are sisters born into an ordinary mage family. Iris is actually the legendary Grand Supreme of Stardust, yet only thirty percent of her power has returned after being sealed by the Lord of the Abyss. To shield her sister from Abyssal assassins, she deliberately conceals her identity and lives as a common‑mage. Only a handful of her subordinates who fought alongside her know who she truly is. Lyra has long been in love with Dylan, the heir to the top‑tier Fire House, and looks forward to their engagement party with all her heart. She has no idea that Dylan has already secretly been involved with Chloe, the Water House prodigy. On the day of the engagement party, Dylan publicly breaks off their betrothal. Chloe humiliates Lyra with magic, pushing her to the brink of collapse. Witnessing her sister being mistreated, Iris stops holding back her power entirely. The ancient stardust magic bursts forth in an instant, overwhelming Chloe's water‑element magic with a single strike and stripping Dylan of his magic, stunning everyone present. From then on, Iris embarks on a journey of protecting her sister and turning the tables. She reveals the truth to Lyra: the Ancient Wind God Bloodline slumbering within her sister is the only power capable of countering the Abyss. She awakens Lyra's Wind God Bloodline. The two sisters expose Dylan's infidelity together, defeat successive assassination plots set by Dylan and Chloe at the academy, and ultimately foil the Lord of the Abyss's scheme to invade the continent. In the end, Iris becomes the Grand Supreme revered by the four great mage Houses, while Lyra grows into a powerful Grand Magus of Wind. Standing side by side, the two sisters become each other's strongest support."