Are Pokémon fusions in Gen 7 already hinted at in Pokémon X or is this just a reference to that Manga?
It's a reference to Bill
It's a reference to the time in gen1 when Bill accidentally fused with a Pokemon.
It's a reference to furfags.
It's a reference to your mom.
It's a reference to Stingulor.
It's a reference to JoJo