Tartaros Chapter - Celestial Spirit King vs. Underworld King Fairy Tail : Season 6 Episode 23

Lucy is a wreck after giving up Aquarius forever in exchange for a one-time summoning of the Celestial Spirit King, who then takes on Mard Geer, the Underworld King. And Lucy finds she doesn't have time for tears as the explosive Jackal tries to take her out of the picture.