User blog comment:Ragadorus/The Secret Weapon/@comment-24.22.211.49-20131026055957/@comment-7387716-20131026123926

Could be plausible. His shield could probably do more than shielding him from attacks. Some sort of energy blast? Or a new function that Jaune doesn't know about (probably his ancestors did knew about that function but Jaune didn't know anything about that at the scenario that he secretly took the weapon and went to Beacon without his family knowing, so...)