I.O is a renowned Chinese STG player who has extensively collaborated with LYX on development of new strategies. He plays various arcade games, as well as Touhou.
I.O has been the first player to have exceeded 2 billion in Hard mode of Mountain of Faith, but his replay has never been submitted to Royalflare scoreboards.
Notable player records
| Mountain of Faith || Hard || Reimu-B || 2,011,279,410 (WR) || 2007/09/08 ||