Successfully performing a coordinated, well-timed attack with Aurene will stun the creature and give Aurene an opening to break through the creature's defenses.
This must be timed correctly with Aurene. Otherwise, you run the risk of Aurene missing her attack window.
— In-game description [?]
Coordinated Attack is a special action skill available to players during the final battle of Precocious Aurene, To Kill a God, and The Crystal Dragon(Although during The Crystal Dragon, it is renamed "Resonating Blast", sharing the name and icon of another skill used in that same fight, despite the real Resonating Blast having a completely different effect.). It usually appears with a locked icon and cannot be used, but when the character and Aurene are standing on the correct white effect circles during a Boss Fight it will unlock, becoming unlocked. When used during the Ley-Line Leecher's attack it will fully deplete the Leecher's defiance bar, rendering it vulnerable to damage.