
Originally Posted by
Buffalobiian
I assumed that because Black Star seems to have reached an agreement with the Stag (inner spirit of the sword. Forgot Never remembered his name).
You're right though in that it doesn't necessarily mean he's unlocked all of Tsubaki's current abilities.
It's just that before, Black Star's main problem was having his soul wavelength zapped by the sword. By the end of Arachne's arc, he was fine with keeping Tsubaki in Demon Blade mode and everything, so I assumed there were "zero problems".