Sentai Core

Early History
The Sentai Core is an aspect of Super Sentai introduced in Jettacosta Sentai Himitsuranger and the Ghosts of Dreamland. The Sentai Core is described as almost a storage bin of ranger power that was created because of the Ranger Keys. Because of this, the never created Spirit Jettaroids, which Jefu already thought about their powers for caused them to become real.

However, no one (other than Yi Chin) knows the existence of it until the endgame of Kaizukuranger, which allowed the Kaizukurangers to sever the Uchurangers' powers and defeat them once and for all.

Later History
At a young age, Yi had come in contact with the core in her dreams and fell in love with creating new gadgets and equipment just like those of the Super Sentai (and the like). She soon became the apprentice of the equally Kelsey Taylor in Hong Kong.

However, when her parents died, Kelsey took her and her brother, Bao, in as her own as she wasn't interested in marrying.

With Bao in Scouting in Hong Kong, he decided to go to the World Jamboree in Japan, his sister and in loco parentis joined him.

Yi couldn't give up work on her new weapon, her changer, Mystic Transformation Device Draco Blaster. However, she saw the thin and Narrow Daipatchi (created by Kelsey) were not compatible with her blaster and engineered her own power set and robo, the Draco Cells.

to be added