I know for a fact that Ragnas 6A beats out Arakune's dives, the only problem I'm having with this is, knowing which side he's gonna land on... his cross-up dives are just so annoying.
And seeing as how I'd probably run into a cloud, or be forced to block one, it makes air-to-air kinda dangerous.
Arakune seems to have a dash/backdash with annoying retarded teleport properties *kinda like slayer*, which they can also go immediately into if they land with their dive. I usually get a free 5B into a combo on wake up from those, i dont know if he's slightly vulnerable as he appears out of the ground or if its just the Arakune not blocking.