Oletus
Twin Outlanders, who ventures throughout Worlds and galaxies. Alas, when the Cataclysm struck and they were seeking to leave the world named Teyvat, they were stopped and confronted by a certain "Sustainer of Heavenly Principles". This, God of somewhat capture the sister, leaving the brother.
Though the God would want to seal the twin's power just for safekeeping, the brother managed to overpowered the God using an unknown magic. This "magic" helped the brother keep his powers, and fend off the Unknown God. But, despite the best he did, both the twin were sent 500 years apart from eachother.
The sister, sent to a time of war, destruction and death.
While the brother, was sent to a time of peace, prosperity and harmony.
Though the brother was separated from his dear sister, he is not worried. The brother have been awake in this world for about 3000 years give or take. And though his sister just recently woke, he is not worried. He awoke near the shores, and immediately makes his way to the "Hidden Veil".
He stayed there for a while, bidding his time. Realizing that his sister would not come to this Hidden place, he venture out of it, arriving at Mondstadt. Along that came with him is his knowledge, wisdom, power, along with a small moth flying around him.