Board Thread:Speculation House/@comment-14312167-20140111211806/@comment-10390252-20140526113728

The rule to remember is Aura is a general power that boosts natural things like senses and healing. Semblance is a narrow ability, powered by Aura, that typically doesn't manifest itself in any way as boosted biological capabilities.

In Adam's case, his Semblance would seem to be the energy absorbtion and redirect effect sometimes called 'moon-slice' by fans. Notice it took him several seconds to prepare himself and this draws parallels in my mind to the ritual-like motions Ren had to use to charge up his force field/force projection Semblance and the way Pyrrha had to completely focus her mind to precisely manipulate the angle of Jaune's shield.