User blog comment:Jopjopjop/Volume 19 Spoilers/@comment-104.7.80.176-20150224020838/@comment-24502975-20150224132143

I think you're getting confused on something. It's not that it was stated to be irregular when it first appeared; Ishibumi recently updated his blog and stated that Kiba's BB is irregular. Not subspecies, not original, but irregular. We don't have any concrete info on what exactly this means, but considering there was some mention of the ability to combine both Balance Breakers, it could be related to that.

Whether or not it classifies as a subspecies even though it's an irregular... It probably would. It's just different from even other subspecies.