[EnerPrime]

Quote:

Originally Posted by Sentai

Though to this day I have no idea why Agito's Final Form Ride was a flying surfboard, or why Den-O just turned into Momotaros.

Agito's FFR was because his motorcycle could also turn into a flying surfboard. Den-O's was , as stated, orginally the Den Liner but switced into Momotaros when Tsukasa helped Momo get over an identity crisis.

I's say the absolute strongest is Decade Violent Emotion. He can use the powers of any other Rider (not just the nine he usually works with) without his usual weak point of having to transform into the specific Rider first. He can Clock Up (and probably Hyper Clock Up too), turn invisible, hit you with all the firepower of Zolda's final vent or anything else a Rider could do.

Decade VE is all the powers of all the Riders in one person. He's the pinnacle of what an unrestricted superpower copycat can do.