Board Thread:Theories and Speculation/@comment-27924662-20170220133905/@comment-25122992-20170221160833

@Namikazenaruto9, I don't think that's the case, especially for Rinnegan's Preta Path (which Momoshiki didn't seem to have, but only a similar absorption ability), since Blocking Technique Absorption Seal generates a transparent shell around the user's body that is actually used for absorption. So it's not like non-frontal ninjutsu cannot be absorbed because this shell covers the whole body, so as long as Rinnegan wielder knows about an incoming attack, he should absorb it regardless of the direction. Thus, he wouldn't be able to absorb the jutsu only if he doesn't see the attack coming, but not because he can't, but because he doesn't have a chance to react and put up the absorption technique.