As a few others have posted, anyone that cries about immersion being ruined are far too late on that. We already got bikini tanks, roe moogles, gear from several other Final Fantasy games, a King Slime hat from Dragon Quest (or Warrior? Meh both are the same to me), turtles that fly with magical farts, and smacking monsters with moogle styled claws for Monks; Yokai-Watch themed minions and weapons seem the LEAST out of place.
I don't really see this crossover immersion breaking that much considering one can easily say that these trends of the toys and mounts came from another land, similar to how a lot of the seasonal events explain how we get certain things.
