I've always been a fan of Dan's Megaman remixes but this is just incredible. Super-neato-coolness! You know how to draw upon your listeners' emotions very well. Damn awesome song.
Not the hardest boss ever but Piastol in Skies of Arcadia Legends is a tough cookie if you aren't leveled (and even if you are she is damn annoying). And using a scythe gives her a +3 awesomeness bonus to her boss rating.