Well I dunno the deal with Dark Rider, I think it's just a NM that passes by really fast sometimes in the area just to freak you out. (but I could be horribly horribly wrong.)

But yeah Odin's in it, his .dat and everything. And he's shown at the end of the trailer if you go look that up. But as of yet no real mention of him in the missions, and I've done them all save the last 2 for palace access. I lack the equipment to get in yet. T_T