I'm not really feeling Rising IXA. It's chest is really flat and looks like a heart is being ripped out of it. On the plus side, he does have a more insect feel too him which is always good for a Rider.
Also I have a theory:
Otoya lost his memory so Maya will make him Kiva and Yuri will become IXA to fight him. Otoya will use Kiva to kick Riki, Jiro, and Ramons(think thats his name) ass and trap them in Doraan.(Who at the time is a cute baby dragon>.<)
And in 2008 Wataru will find Otoya at long last only too find out he got lost inside Doraan for all these years.......>.>