I love almost everything about this, which is something I've never said before for ANY song on Newgrounds. Honestly, for a fourteen-minute-long song, I don't think it would getting boring fast. The mixing is very, very, very professional, the percussion is amazing, the Asian instruments are stunningly beautiful and conjure up images of snow-capped peaks, deadly needle-like katanas, ninjas clothed in shadow, and also metal guitars. Maybe iron. Or steel. Carbon, even.
Bro! I love those cheesy synth toms at 4:17! They remind me of the intro to Rick Astley's Never Gonna Give You Up.
One thing I have against it: the intro is awfully long and slow. This does add to the feel in some ways, but it could probably be cut down without losing any of the epicness.
Also, your transitions are so smooth! If I hadn't already listened to Koto Overdrive I wouldn't have ever guessed that this isn't all one song! Instant favourite. Keep up the great work, ALESDA!