Ika Devil. He's one of the villains from the original Kamen Rider series, it's where Iga got his name.
did anyone notice in the "final" episode of decade where DiEnd and Decade both did a Dimension shot, DiEnd gave a Form Ride card to Decade but the DecaDriver said FAR DiEnd.. wierd...
So wait, Tsurugi actually lived in Castle Doran!? LOL...When I was watching Kamen Rider Kabuto Episode 34, this one looks very familiar. Same frames from Kabuto and Decade.
Decade - Kiva's World, part 1:
Same place. Same frames. Gotta love it.