Pokemon Masters Ex fanarc Vol 1 ( Chapter 4: the Cores, Chapter 5: Flanerry's fiery passion)

Chapter 4: So if you are wondering why Y wants to find the Zygarde cores, well here is the answer: right before the kalos friends left their own ways (Shauna, tierno and trevor went to form their own group for the PML while X joined korrina's group), proffesor sycamore (who wouldnt appear till about chapter 24 or later) tasked her to find the zygarde cores before team flare could get to them, he is also working with proff bellis, clavell, and oak because they think somthing's fishy about lear, his hoopa, and the PML. During the search, Y decided to join a group consisting of: Moon, Lillie, and scarlet (very important), and after the group decides to split between zygarde core tasks, and the PML, Y notices a gift from shauna and shouldn't open it till necesaerry (later the gift will be revealed in chapter 53 or later)

Chapter 5: After Pearl Joined the group, they decided to find flanerry to help them win the PML, when they find flanerry they battle her, but during the fight, bettie's squirtle egg got damaged but it helped her pikachu defeat flanerry's torkoal, after flanerry joins the group, they encounter team break who plan on stealing scottie's charmander egg and bettie's squirtle egg

TBC in chapter 6: What Odd Hatchlings!