Kamen Rider OOO and Some Throwbacks to Its Kamen Rider Predecessors
As far as I can say, Yasuko Kobayashi pretty much likes to recycle previous plots while adding her own, similar to Toshiki Inoue. Looking at these, here are some of the similarities to previous series:
Eiji Hino like Yuusuke Godai later has the possibility of losing his humanity. When Eiji gets the purple medals to access the Putotyra form, he is at the risk of losing his humanity. I just thought it was pretty much spice to the show to avoid the show from becoming too light. So here we have a bit of copying from Kuuga.
OOO basically had the Cous Coussier. Kuuga, Agito and Ryuki also had them.
Apparently the designers for Kamen Rider OOO ended up making the Greeed look like the Lords. The Greeed like the Grongi are ancient enemies of mankind. The first OOO fought the Greeed while Kuuga fought the Grongi. The Greeed also like the Imagin in Den-O take advantage of desires to carry out their dirty schemes.
Ankh being a douchebag protagonist can be traced to the likes of the annoying Masato (Faiz), Nago (Kiva) as well as Shinji, Renn and Shuichi (Ryuki).
Dr. Maki's role in Kamen Rider OOO does kinda copy a lot of previous works. Killing his own family? You got that from Takeshi/Ouja in Ryuki! Wanting to bring the end of the world? You got that from the Lord of Darkness from Agito! While I thought he had a boring personality, but I would admit that the final battle with him was sort of similar to Agito. So like the Lord of Darkness, Dr. Maki in his Greeed form attempts to end the world at his own convenience, and also he is given that really super high leap attack by OOO which defeats him for good which happened at some parking space like the Lord of Darkness was defeated at some park in Agito.