It's Taki Kazuya, a character from the original series, and the "Rider" costume he makes is an homage to Ishinomori's Skull Man. I thought that was a really cool touch, bringing Taki back (he's like the proverbial great grandaddy of sidekicks like Ichijou or Kagami)
It's basically a greatly expanded retelling of the Kamen Rider ZX story, set a little more in the present (I think, they have e-mail, did we have that in 1984? :laugh: ) And there are TONS of references and nods to the earlier TV series (the original~Super-1) and a couple ideas that for many years just existed in offscreen limbo (the story of how Riderman survived, all the MIA Badan Kaijin, what happened to [Insert Character Name], etc) finally get to see the light of day, so of course it's like a dream come true for me.
Spirits is still going strong in the monthly Magazine Z. I downloaded the first translated chapter waaaaaaay back, did that group ever do any more?