Umm......what rock you living under? The Capcop rock?
Kosy is one of the best players across most fighters in state, Melee is one of many games he plays very well. Indeed 2D fighting gamers that picked up Melee after specializing in older titles actually expanded their horizons on games played alot. Pablo, Matt, and Kosy are just a few examples. Excellent players.
Kos Mos & Sephi are pretty good at Marvel, AH3, and Melty Blood right now. They tend to excel at more technically complex games (IE MB, BB, AH... although they play SF4/MVC3) Alot of people fall in and out of MvC interest pretty fast it seems.
Hanson Le is also ♥♥♥♥♥ raping hard in Marvel.
Kosy took like 14th out of 109 in MBAA at evo byo last year.