8 Should this fanfic be multiverse? [Animes with Guns like Trigun, Cowboy Bebop, Pyscho pass Ghost in The Shell, Resident Evil etc

[Animes with Guns like Trigun, Cowboy Bebop, Pyscho-pass Ghost in The Shell, Resident Evil, Lupin the 3rd, Jormungand, Madlax, Gungrave, Black Bullet, Gunslinger Girl, Hellsing, Canaan, Black Cat, GantZ, Cyberpunk Edgerunners, Suggest any other anime with Guns

Let me know if this fanfic should have multiverse.