Describe a character who has a mysterious past and goes by the name „Ki

Describe a character who has a mysterious past and goes by the name „Ki.“ They are skilled in martial arts and have a talent for solving puzzles and deciphering codes. Despite their enigmatic background, they are fiercely loyal to their small group of allies and will stop at nothing to protect them. Ki’s true intentions and motivations are shrouded in secrecy, leading others to wonder what secrets lie beneath their calm and collected exterior.