Play with the selected character

good afternoon, I'm working on a project 2D, where I am implementing the option character selection; are five players, but I can choose to play with either of them, what I want is: when choosing a player, that player appears on the scene, but just once; and if I decide to play with another, pass the same as the previous, but that previous, move according to AI. (I have already the AI ready)

Some tutorial, any idea....

Thank you very much