User blog comment:Trogdor7620/Requiring Assistance/@comment-18530805-20140508115332

From experience, such an ability would be OP even with the weakness. Also Semblance may come from aura, so Grimms wouldn't be affected. Why? Grimm do not have aura, thus they cannot use aura. The example you gave was merely a technique the Grimm implements, similar to how Nevermore can shoot their feathers out similar to a gun. Notably, you'd would also have to make it only one power, but again the power you copy has to be dimmed down: say similar to how copycats don't have the full power. In this case, Ruby's speed wouldn't be as fast, but increases Darrel's base speed or if with Yang, the fire's range wouldn't be as large or as strong. Limiting the Semblance's copy power and only able to copy one at a time, then there'd be some balance.