Rapyuta
Rapyuta is one of the most famous KGS players - grand 9d blitzer who only few can compete with, with considerable following. He's known for extremely fast reading, often playing a move in the first second of the 10 second byo-yomi, which makes many of his followers suspect that Rapyuta might not be human. His style is very flexible, often employing unconventional openings to achieve superior result in the beginning. He has detailed knowledge of some of the most complicated josekis. A mistake by an opponent who doesn't know all the trick moves often gives rapyuta an early advantage. He's best remembered for his superhuman feat of playing a total of 79 blitz games in the time span of 12 hours from 9/16/07 3:00 PM to 9/17/07 3:10 AM. It's unlikely that rapyuta even took a bathroom break! He won 52 games.
http://www.gokgs.com/gameArchives.jsp?user=rapyuta&year=2007&month=9&oldAccounts=y
There are many speculations on who Rapyuta is. Macisajt knows Rapyuta in person, and he is believed to be an insei of Kansai Ki-in. Reportedly, he almost made it to pro several times.
Anonymous: On March 5th, 2009, admins on KGS removed his rank permanently, due to his policy of resigning against bad players, giving them inflated ranks. He then created a new account called yagumo. During late 2009 and early 2010, Rapyuta played as Erinys and Elona. However, on March 11th, 2010, both of these accounts were deranked for resigning won games.