SOME of you seem to be avoiding a little logic sense here. Kuuga in the original series worked pretty goddamn hard to start off with, and if you compare him to in the final episodes, you could clearly see how even he had difficulties battling Daguba as Ultimate Kuuga. And that's with tough training throughout the entire series.
Some of these riders don't even TRAIN. Kiva was shown not to even do push ups.
It took Godai a MANY trials before he was actually able to control Ultimate's power. And that still was only able to rival Daguba.
And someone said earlier that Agito probably could, I disagree. It's not possible for Agito to charge up all that power from Ground Form... The whole endless evolution thing is in terms of FORM changing, not power-wise.
Despite Momotaros help, Den-O would be Daguba's toothpick.
Blade and Kabuto are probably the only two that could escape. Clock-Up and Time Card. But I doubt they will be able to defeat Daguba.
It's not only about the amount of Riders there, it's also about their ability to fight if you're gonna go against Daguba. What is Decade when Daguba could easily just light him on fire as soon as he starts to speak "I'm a passing through-".
Sometimes we've got to imagine what some words mean too... "The Ultimate Darkness" in the original Kuuga was a very scary thing. But in Decade, it was made to seem as if it was kinda pointless cause he'd kick your ass anyways.
I rest my case, Daguba.