"Trap Phantasm", which is Prometheus & Pandora's theme from Mega Man ZX Advent (the image in the video shows the game's protagonists, Grey and Ashe, though
). The track itself is a remix of their theme from Mega Man ZX, which was called "Trap Factory".
I'm currently digging through the Overclocked Remix archives. Here's a pretty amazing improvisation by Samuel Ascher-Weiss lasting over eight minutes. He has an amazing musical talent and many if not most of his pieces require your full attention to truly appreciate their depth and composition. Good stuff.