My brother, Midas Longsnoot, had an idea for an item called the silver handbell. When used the item summons a preferred Retainer to your side kind of like how using Gyshal Greens summons your Chocobo. Additionally, you could add a way to incorporate depending on what class you gave the retainer and how much you leveled it (Devs. can decide which X.P. system) it can help you at said level. Just a cool thought for a great potential companion kind of like how FFXI did with trusts