Shiranui saw Sashia perform a similar dance to the tourist back at Vermilion.  "That's one of those Z-Moves!  Yoto, King's Shield!"  Yoto's shield gave off a brief flash before the Aegislash was engulfed in shadows.  When the shadows disappeared, Yoto had taken major damage, but survived the powerful move thanks to his shield and high Special Defence stat.  Shiranui discovered that Z-Moves cannot be fully protected against and he lost a lot of points from the move.