There are multiple artists called XI: 1) Xi is the name of a doujin artist from the circle AQUAELIE that makes metal arranges of touhou music. 2) xi (Yusuke Ishiwata) is a Japanese music producer known for his BEMANI Simulation Files (BMS) and for his appearances in Rayark Games' rhythm series Cytus, which made him quite popular. He has been a member of the 100sec Records label until March 31st, 2014 and often appears in Diverse System compilations.