Hmmm, a while ago I was reading some old Bleach chapters and one of them was the one where Jugo executed Cang Du and BG9. Jugo was mumbling something about 'keeping the balance' when he executed them. When I first read that chapter I just considered that some random gibberish Kubo added, but when I read it recently again I started wondering whether that isn't his actual power: keeping balance, whatever that means, and that his letter "B" stands for "Balance". The latest chapter seems to have gone into that same direction. Jugo is Yhwach's "other half" and he can't use Reishi and make a bow like normal Quincies, so both of them can be translated into that he is keeping a balance. This might also be an additional reason as why he wasn't selected as Yhwach's successor as he is the one who needs to keep in balance to the successor.
Though, as said, I haven't the foggiest what keeping balance would mean.