Fairy Tail Wiki:Relación Seis/Thunder Gods

Wally Buchanan
Erza and Wally Buchanan have been friends since their childhood, having both been slaves in the Tower of Heaven, as well as members of the small group of children led by Jellal Fernandes. While initially shown willing to kidnap Erza alongside the rest of his group to take revenge on her for supposedly leaving them behind in the Tower, after hearing the truth and being told of her innocence he shamefully apologized to her, regretting his former actions. When Erza intecepted him, Sho and Millianna while the three of them were trying to leave during the night out of shame for what they did, she gave them a tearful farewell ceremony in Fairy Tail's style, complete with fireworks which her teammates set up; something which left Wally deeply moved, prompting him to promise that his and Erza's paths will cross again.

Millianna
Millianna is another childhood friend of Erza, and, like her, a slave girl, working for the construction of the Tower of Heaven, who used to be part of the small group led by Jellal Fernandes. Believing that Erza had betrayed them, Millianna took part in her kidnapping, restraining Erza's comrade Lucy Heartfilia in the process. Following the revelation of Erza's innocence and their escape from the Tower, Millianna apologized to her for what she had done. Later on, when she tried to leave Erza in the night alongside Wally and Shô, regretting her actions and not wanting to upset her friend with memories of their past, Erza bid farewell to the three of them with a ceremony typical to Fairy Tail, complete with fireworks set up by the rest of Team Natsu. Millianna was deeply struck by such action, shedding tears of joy as she left.