Basically, LB from PvP jobs, where we get our own unique LB bar rather than just a party bar I assume.
Tbf, it could go on everyone's gauge as a separate LB gauge, and this gauge could be charged using AST's cards... giving some spice and variety there... so I can see how it can be fun with it.

It can consolidate and help remove /adjust skills to make sure it's not overpowered or unbalanced. I don't know if that can be implemented so soon though since it would affect every class.