A Scooby Doo licensed game developed by Atlus that plays like a Persona game. Think about it. And yes, that fan art already exists, because of course it does.
Found with a quick google search sending me to Neogaf.
This dumb idea has been brought to you by me falling down a deep, dark Persona 4 and SMT4 hole (since I never finished SMT4 last year), from which I will surely come back a changed man. But hey, Chie or go home am I right?