Bradley's Ultimate Eye and greater endurance should be enough to give him the win over Kenshin.
I was thinking the same thing, however, even with the ultimate eye, some of kenshins moves would still be difficult for Bradley to block or evade, and een if he managed to do that,moves such as Kenshins Amakakeru Ryu no Hirameki would just return with a vengence.Also, even with Bradleys endurance, he still has the physiology as a human which kenshin can still exploit as seen during several of his fights
The only thing kenshin has got going for him is his fancy moves, in terms of overall stats (speed, str and stamina) bradley has got this under control. Kenshin needs help from a member of Aoshi's gang to beat a gatling gun while bradley can chase down a tank then kill it with only a sword and grenade. Kenshin aimdodges from reacting to his opponents, bradley can cut bullets in mid air after they are fired. Bradley FTW
There is seemingly no 'perfect' way to truly say goodbye. So I gathered a bunch of them!