Even if they weren't allowed in, it would be perfectly possible to shoehorn in such a character acting as a spy/covert agent/hostile element/hidden element. Good ol' Jesus Suit Mickstone, with his giant crosses and gold crucifixes, is actually Jesuit Michstein with stars of david hidden in the basement chapel of his mansion. Done. Can even just be environmental storytelling and never actually brought up, an easter egg for people who explore the game.