Board Thread:Speculation House/@comment-72.235.216.156-20171121223945/@comment-26397825-20171204010748

We have actually seen a glimpse of Jaune's semblance; when Cardin was beating him up and there was a bright flash of light. When the flash ended, Jaune was glowing and Cardin was on the ground holding his wrist as though he was the one who got hurt instead of Jaune.

The most common theory is a reflection semblance; he reflects damage back at the attacker.