Winx Club (2004)

S4E24 The Day of Justice

The Winx girls arrive back in Tir Nan Og alongside the Wizards of the Black Circle, only to find themselves facing a fierce battle to protect the magical realm. In a heroic act, Nabu sacrifices himself to save the kingdom, leading to his tragic death. Devastated, Layla is consumed by a desire for vengeance over his loss. Ultimately, she decides to part ways with the Winx Club and aligns herself with Nebula's army.