Cloud is around Zack's level reaction-wise, but that statement seems to be putting Cloud higher and/or handing Zack's uber bullet-dodging feat from the canon anime to him...nuh-uh. Just no.
Sora dodges/hits back bullets (Pirates of the Caribbean world). Cloud dodges bullets.
Terra.................have not touched BBS yet, but have seen from the secret ending in KHII that he can fall of cliffs...get electrocuted...frozen...smashed with hundreds of keyblades....and still fight like a badass.
-Edit- Holy crap Blood, 5:27 shits on ANY speed feat I've seen of Sora! Even the one beyond the double doors of KH! As well as the lasers.
Good shit. 😱
Reaction-wise Sephiroth's attack I heard is dubbed Oblivion which in Dissidia is described as a light-speed attack in an Ultimania. However it simply resembling that attack in KH2 doesn't make it the same IMO. Heard from somewhere that the Dissidia move was based on Sephiroth's KH2 attack, though didn't buy it much.