Sounds good @mattmanganon! It's a bit out there, but as a big fan of Dr Who I think that there's a lot of room to have fun with him interacting with the different heroes. He's fundamentally different to almost every single one's approach to solving danger and conflict; that's bound to introduce a lot of drama. And given how different this world is because of this amalgamation, the Doctor having a lasting effect throughout the period, even from the very beginning, might make sense. But I'm happy to discuss this further with you - I'll decide on which Doctor I'll be using soon.