The Tower Of Heavens
What if Lucy was in the tower of heaven? Not only that, but she was friends with Erza's group of friends, along with the Oracion Seis?
This is an alternate universe where Lucy was in the tower of heaven. Where she met both Erza's and Cobra's group of friends.
Not only that, she was forced to help build the tower with Simon, Sho, Wally, and Millianna. But this is the new and approved Lucy, who knows a deluxe version of dragon slayer. She can use every dragonslayer magic.