Aaron is a orphan he was taken in by Natalie, She cared for him but Natalie had to hide him away for fears of Gabriel doing something with the boy. Natalie grew weak because of the peacock miraculous, Aaron could tell. Natalie had hidden him away in another place coming to visit when she could to give the boy food. Some days Aaron would starve for Gabriel did not make it easy for Natalie. Once the peacock miraculous was fixed Natalie continued to help Gabriel but she was too weak....And the mercy of the miraculous was not given. Aaron finding out weeks later snuck into the Agrestes household stealing the peacock miraculous from under Gabriel's nose. He has hated Gabriel ever since and wants revenge. He wants to bring back Natalie if possible. Though Ava is also an Agreste Aaron has gotten close with her and considers her to be a great partner.
(This story is of course fictional :P)