Star vs the God of Evil fanfic here:

Introduced in Chapter 9 of Star vs the God of EvilOrion, son of Star God-Mother.From an alternate universe. Son of Evil, son of the Republic, a young gleeful child born on a god world. A happy child hiding a secret sadness, knowing the nature of his father, while also suspecting other secrets his mother is keeping from him. Secrets that will shatter his world views.His cheek mark is a balance scale symbol. On New Mewni, the gods can choose to have cheek marks, symbols representing their godhood in the new world. His mother, the most powerful god of them all, by choice, decided to leave her cheeks empty. Orion isn't quite powerful enough to keep his marks on permanently, yet, thus he feels inadequate because of it, always wanting to live up to his mother's greatness.