Ju-Long cannot reach soul resonance, because what he has is not the resonance between meister and weapon, but instead a familial bond, like Liz and Patty. They can wield each other, but they will never be as strong as a Meister and Weapon pair, because their wavelengths are too similar.

By the way, I forgot this, but please add the appearance of your soul to the CS for the benifit of those who can see them.