User blog comment:Xilinoc/Ch. 618 - The Dark Arm/@comment-1747976-20150305234422

Actually, he didn't try to destroy the SK and Mimihagi with some 'javelin shadowy thing' but rather, he tried to reach for the SK and Mimihagi was able to stop him from breaching the barrier in that frame. This why he said the he couldn't believe that it would be possible for him (SK/Mimi) to 'prevent this singlehandedly...' That black reiatsu or what ever it was that emanated from the spot where Yhwach tried to reach in with his hand....... the second strike would have been the one to break through.......