Wow, it's amazing. Makes up for the screechiness of OP 5 and more. FLOW has to be the best rock band in Japan. Oddly enough I don't mind the Engrish, it's actually comprehensible if not grammatically correct. Despite the energy there's a darkness and sadness clearly evident that fits the part of the story that the next 26 episodes are going to cover, an emotion the previous two FLOW OPs for Naruto didn't have.
Good animation (hell it got amazing with Naruto in the sanRABtorm), great, highly melodic composition. This song has heart and soul put into it, just like CLOSER.
I cannot wait for the full version.
And when this song finally gets spun on DXD I'm going to play it full blast the first time it plays. Mark my worRAB.