Without items, Bowser has far greater physical strength while Dedede has far greater speed. But Bowser barely takes durability. Dedede takes intelligence/strategy. So that means Bowser is physically superior overall while Dedede is mentally superior overall. I would say Bowser via hax, more powers, and Giant Bowser would be too much, in my opinion. Masked Dedede would be needed to even have a chance against Giant Bowser, IIRC. With items, it's Star Rod, Dream Stone, Minimizer, Hammers, Bombs, etc. vs Warp Star, Star Rod, Hammer, etc...I would say Bowser wins in a close fight against Dedede in a 1v1 match, but he wins in a not-that-close fight with items/weapons. Also, Bowser's horrible temper has been shown to somehow make him extremely powerful before in games such as Super Mario Galaxy, as he made the universe shake with his deafening roar after Mario hit him twice with meteors. Not to mention Bowser has a far greater # of powers such as gravity manipulation, reality warping, pyrokinesis, etc. Dreamy Bowser and Paper Bowser are too much, in my opinion. Lol! Also, the creator of Mario confirmed that Mario had no canon, so the Paper Mario series counts as part of the Mario series.