The floor grating above inner keeps' main door way, that people pour oil through, IF you are standing on/near it and get hit with a knock-down effect that knocks you onto the grating, you fall right through the grating and hit the ground below. 1st time it happened, the fall killed me. Few days later it happened again, and mob below killed me instead. Both times, I was hit with those lighting bolt things. Another time I was using Draining shot while up there and hit a guy, who promptly disappeared...... through the grating. Kinda funny tbh, but annoying when trying to defend a keep.