[Shin Henshin]

As out-of-nowhere as the final Decade episode reveals were, I can buy the Ghost World and Space Squad connections. Robo-Sougo feels more like he'd be from Kikai's AU than anything else, since I feel they'd at least throw something on his ear after the reveal that showed he was actually a humagear.

Personally I liked both mini-series overall. Decade's was the weaker one mainly for the final episode's rushed ending leading into Zi-O's story but as an overall thing it was plenty of fun.

Ohma Zi-O's overall goal of restoring himself only for it to become a last-minute "You thought you defeated me? You'll BECOME me!" before exploding was very on-brand for the character. And he's technically not wrong with how his relationship to Sougo works. He just ensured he'll exist either way by being the true Sougo. Also the conflict of space and time with Decade going after Ohma Zi-O was a good touch. Stuff like Narutaki being forced to work with him in the space between dimensions (Which is absolutely a thing cause it was also used in Super Hero Taisen) was cool to me.

Honestly, all the little details and such really does make me wish Zi-O ended with a reveal that it was a Decade prequel. There's tons that could have supported it, even here.