This is a book of Mary Sues doing Mary Sue stuff. The characters are the Sue Siblings, cared for by Mary Sue and Gary Stu in the Sue house.

Percy Jackson: Cynthia Amari Diamond-Rose, Daughter of Artemis

Wings of Fire: Aurora, Savior of Pyrrhia, Defeater of Raven

The Owl House: Amaya Tellen Oakus, Owner of the cursed staff, In every track just like Luz

SVTFOE: Stella Lucitor-Butterfly, Daughter of Star and Tom, Savior of Mewni

Steven Universe: Moonstone, Ally to Purple Diamond, Little sister to the diamonds

Morrigan Crow: Ignis Lumos, Controls fire, the only male in the Sue family

Harry Potter: Pearl Valentine Weasley, Sister of Ron Weasley, In two houses

I will add more soon!