I recently had a Cathedral Knight in the Cathedral of the Deep (a.k.a. the Red-Cloth version) use Force on me. That was the first time i've ever seen that. Btw, it was the one with a Great Mace that's sitting on a bench towards the end of CotD, i had also killed everything nearby except the Hollows that are also sitting there. I damaged it with a heavy R2 to get huge damage in and make it get up, once it got up it used Force.