Hey, Sparton, I'm not sure if this is a glitch or not, and I'm not entirely sure what happened, but I was in the arena up against a team that had the Assassin Golden Son. He activated Endure, and then either his Eddie or his Nomad attacked my team that had void shields and suddenly the only one on his team that had Endure still was his Nomad.

Or, I've had some times in arena where after my void shields have been used, my Magus Harpy still has hers for my turn.