Putting the original ten Kamen Riders (Ichigo, Nigo, V3, Riderman, X, Amazon, Stronger (and Tackle), Skyrider, Super-1, and ZX) into Homestuck I think would end with the Great Leader getting prototyped and acting as the Mega Cancer that Bec Noir represented. I will not classpect the Riders at this time, however I WILL say they would likely be able to, at least, do all their land quests and the smarter ones (particularly Ichigo) will be able to alchemize the Genesis Frog and make a new universe.