The issue with using the espada Rukia fought is that the feat that is supposed dodging light is perform the same way a vampire or Batman would dodge the light from blinds or a window. It’s not an actual light speed feat.
The only reason I’m okay with character being this broken in the beginning because they are gods, soul reapers/ grim reapers. They must battle demons (hollows) and sometimes each other (the kenpachis). They are mainly spirit so normal logic won’t limit them.