>>57542079If both Mario and Link have had several cameos in each other's universes, small cameos like the Keaton Mask in Zelda shouldn't be a problem.
For example, a pair of plumber brothers in Unova (in the equivalent part of Brooklyn) Linguini selling you TMs related to the Mario universe. When you buy enough, as a special bonus, you can face their older brother Mariano using various Pokémon equivalents to characters from their franchise: turtles, squids, mushrooms, and, like Ace, a bipedal Dinomon.
Or a green-suited Pokémon Ranger NPC in a forest hired to search for a missing blonde girl. If you help him, he rewards you by giving you a Shiny Honedge.
A sidequest where a villain kidnapped a girl and is on the top floor of a building, in the final battle he uses a Rillaboom.
My point is that they don't necessarily have to be clones of the original; a friendly reference is enough.
