User blog comment:WeissSchnee/New Information/@comment-13488655-20130824064957

I don't think hers is unlocked.

Ren was able to knock a giant snakes head off, but Weiss needed the dust in her sword.

She was unable to sense the Grim or Ruby approaching.

She also seems to be afraid of the Grim. She was took a number of seconds to regain composure in the battle against the wolves, that never happened against the giant armour.