Lumin

In the pantheon of gods, ruled by the eternal elements, two luminaries—the Sun and the Moon—have always been pillars of balance. Each of the great gods eventually gave birth to heirs, demigod children destined to serve as bridges between the divine and mortal worlds. Children of Fire, Water, Wind, and so on.
But the Child of the Moon was not among them. No one had ever seen him. Whispers began to circulate among gods and mortals: was there even an heir? Perhaps the mighty Moon God, cold and aloof, had proven sterile? Dark deities—Wrath, Envy, and so on—began to attack him, or rather, his supposed weakness. To their surprise, however, the Moon God repelled each attack with icy calm. This raised even more questions.
The true story was hidden from everyone.
The truth was far more tragic and dark. About two decades ago, a dispute erupted between the Moon God and the Earth God about the very nature of time and legacy. Earth believed that everything must grow, age, and die, giving birth to the new. Moon, however, saw eternity. Their verbal battle escalated into conflict.
In his rage, the Earth God dealt a treacherous blow to his most precious possession—his son, the young heir (Lumin), who was then in the prime of his 27th year (by human reckoning). The Earth Curse warped the very essence of time for the youth, reversing his physical body and perception of the world to that of a nine-year-old child. He began to appear small.
But the cold wrath of the Moon God proved more terrifying than the hot fury of the Earth God. In retaliation, seeing the other parent gods watching with a mixture of horror and curiosity, he pronounced a universal curse on all the children of the gods: "If you allow one of your kind to take away my son's future, then all of you will lose your divine inviolability. From now on, your flesh will become half-mortal, like that of humans! You will know pain, the fear of death, and vulnerability!"
True love was supposed to be the mechanism for saving her son. A love that recognized Lumina as an adult soul.