[FairyKing]

To be honest, Fourze has enough major differences from W that calling it a rip-off sounds ridiculous to me. Especially since most of the similarities the OP pointed out are either common tropes that a lot of Rider shows have (Den-O literally had a whole group called "the Taros" because all their names ended in -taro, including the main rider) or are just very superficial.

The monster also being the victim is a very interesting element, to be sure, and I did like the way both shows handled that. OOO did something similar with the Yummies, even though the victim didn't always physically transform into one, they were still acting on the victim's desires. It was an interesting three years in Kamen Rider, where it wasn't just about beating up the monster but about dealing with the problem the monster represented.

Gaim, Build and Zero-One also have monsters that were transformed from victims, but since the victim had no control over what the monster did, it didn't really have the same narrative impact. And Drive had a couple monsters that were transformed from humans and acted on the human's will, but they weren't shown as victims, only as villains (to be fair, W and Fourze also had plenty of Dopants and Zodiarts who were purely villains, but also some who were sympathetic villains and some who were purely victims, which Drive never had).

I guess another interesting connection you could draw between W and Fourze is the theme on connections between people. W puts a lot of focus on the partnership between Shotaro and Phillip, while Fourze is all about the friendship between Gentaro and... well, everybody really, but especially the rest of the Kamen Rider Club. Again, I think OOO is part of that trend too, with how central the relationship between Eiji and Ankh was to the story.