Sasaki Sukai was born nineteen years ago in Sunagakure. He exhibited extraordinary control over his chakra from a young age, such that he was able to learn basic practice jutsu from his father, Hisui. It was the mark of the prodigy in the making, and that was most encouraging for the the Sasaki. They were a prideful clan, after all, and every offspring born to greatness would further secure their relationship with the Kazekage. Sukai was brought up with such ambitious political goals in mind. In retrospect, they would give him a certain impatience with - perhaps even hatred for - politics.
At the age of five, Sukai underwent the very same ceremony all members of his family do. The branches gathered together and placed a seal upon him, granting him the powers of the Sky while forbidding him the strength of the Land. It was another partial cruelty of his birth, a means of securing Sasaki interests and rendering his future a predestined matter. Nevertheless, after the ceremony was performed, Sukai would grow up and exhibit an exceptional talent for the style the seal had granted him access to.
Sasaki Sukai was a prodigy, and there could be no doubting that. He was admitted into Sunagakure's shinobi academy at age six, and by age ten, he'd developed Sky Manipulation in functional fashion. He made Genin by age thirteen, and was considered to be a Master of Sky Manipulation by age fifteen. Somewhere in the interim, he'd even found time to learn Fire Manipulation and an expansive talent for swordplay. It was a meteoric rise to power, and for someone to master the Kekkei Genkai at only ten years was a remarkable thing.
Sukai made the rank of Chuunin at sixteen, with his advancement having been held back somewhat for two reasons. The first was concern over how quickly he'd developed his power, and whether he had the discipline necessary to wield it in a rank of leadership. The second reason was an evolving love of bad habits. Debauchery, pranks, and a shifting orientation between benevolence and something darker. It seems that, when he was so taken with his element, he began to change just as swiftly as its currents would. That would hold true with his future, as well.
At age eighteen, Sasaki Sukai formally left the ranks of the Sunagakure shinobi over the objections of his family elders. His departure was formal, thus avoiding the title of missing-nin. Since then, he's been wandering wherever the winds take him, only to return to Sunagakure from time to time. What motivates him these days is a mystery, and as his usual, his erratic and unpredictable behavior makes solving the enigma none too simple a task.