Alright I'm back at the Leviathen and I'm about to go against Boss Judge again.

I have a quickening for both Vaan and Basch.

I tried to use it on Judge and his guards but I did'nt know how to do it! I pressed R2 randomly and I only got him down half way.

How do I use it?

and if I do it right will I destroy him in one hit?