Hey guys! So, I've been thinking about the summoning of the Celestial Spirit King (CSK). It can't be that Lucy is the first celestial spirit mage to ever summon the CSK. Probably her mom, Layla, was also able to summon the CSK before. With that thinking, seeing as all of the 12 Zodiac Gold Keys were intact (not broken) before Lucy summoned CSK during the Tartaros battle, there could be a way to restore the key. Unless, other celestial spirit mages before summoned the CSK using a different method.