Well, there are plenty of ways you can! You can start the way soundofmind did and introduce your character on his own before interacting with others.
You could push him to butt into the conversation of Dakota and Alexander.
Or you can even introduce him as the figure Carmon is currently hunting down.
He can be an ally or an enemy, either works! I tried to make this as open as possible so that there was plenty of free rein on designing and writing.
