Board Thread:Speculation House/@comment-10380701-20131018004029/@comment-3146930-20131220210756

ImposterParrotGrass wrote: Do you have any ideas or what Juane's semblance is?

They mention in the DVD commentary that the shiny flash of light when Cardin punches Jaune had something to do with his Semblance. I don't think it is healing as Jaune still had his bruise after the fight with the Ursa; but as stated above, it could be some kind of strong shielding ability.