FenzyFirenze: It all depends on how much energy she can output and how concentrated she could apply it. With the ability to just generate force, this could be an incredible offensive power, but let's just say she can't focus it to a point where she can only lift objects. If the object was heavy enough, inertia could do the job of blocking a sword (at the cost of mobility). Applying more force to moving the object against the sword strike would also work, provided the object being used as a shield can take the blow without being shattered. It may be a good idea to see how much force Katia can exert on an object via commands.