Getting Pulled Into Another World

(all credit goes to thunderclap, shagohad12, and Voldine of fimfiction.)
A young man goes to a convention and finds himself in Equestria with the powers of a Kamen Rider. Not just one though, ten of them. And he'll need that power to fight the hordes of monsters lurking in the shadows. Can he face this threat? And can he protect the ponies that call him friend? The answer to both of those questions is: Henshin!