Of course, Erxando didn't become that fast at all. The one flying was none other than Kentucky, who couldn't be detected thanks to Rean's Light Bending and Xian's Shadow Energy.
As a Middle Stage Sky Space-Time Realm, Kentucky's speed while flying was unmatched even for the twins. Kentucky definitely could fly faster than most Peak Stage Divinity Realm Experts, except for some who also focused on speed.
Then you might ask, isn't Gidui a Level Three Umbra, something equivalent to a Semi-Celestial Realm Expert? Shouldn't he be faster since he is also an Umbra focused on speed? The answer was quite simple: Umbras can use more laws thanks to their various memory fragments from multiple experts. However, they don't have the support of Divine Energy, let alone Sky Energy like Kentucky's.
