The Mask Descends: I Can Only Transform into an Aberrant Rider

[Anime Crossover, My Teen Romantic Comedy SNAFU, The World's Finest Assassin Gets Reincarnated in Another World as an Aristocrat, Miss Kobayashi's Dragon Maid...]

I transmigrated into an era where Kamen Riders roam the world alongside monsters, and awakened a System: the Strongest Another Rider System. I thought I'd be able to punch and kick my way to being invincible, but the world turned out to be far more complicated than I'd imagined. There are dragons, angels, and demons. And wait, why is Hachiman Hikigaya here too?

[This story takes place in college. The main characters are all adults.]