Queen

Queen (also known as the Merciless Queen) is an expert sniper that works for Cartia. She was given the Queen Gate by Cartia to challenge Rio to a Gate Battle which involving shooting targets inside a wind tunnel. At first Queen had the upper hand due to abilities, and attempted to cheat by knocking Rio out. However when the wind in the tunnel was temporarily shut down due to Linda's head getting knocked off by Anya, Rio used this to her advantage when the wind was turned back on and claimed victory.