Darth Azard, very solidly. He stalemated a powerful, senior Imperial Knight (and implied the Knight in question knew he wasn't strong enough to beat Azard- even after Azard dismissed stormie support), and has more force in both power and range of abilities (has lightning, unlike Tol. Has a strong force barrier that withstood a strong explosion. Etc.).
Azard's one of the strongest One Sith out of the inner circle in a position of major power. Skorr's just some acolyte.