(a few characters added automatically, but you can add in your own 😁 sorry long starter-)

You went to the convention but there weren't any cosplayers. There were a bunch of fictional characters in real life. Alastor and Sukuna were chilling together, probably plotting murder. Mahito was trying to cause chaos with Choso, while Gojo and his students, Yuji, Nobara, and Megumi tried to stop him. Geto was questioning why Kenjaku was in his body. Atsushi was sticking with people that were familiar to him, like Dazai, Chuuya, Kyouka, and Akutagawa. Sigma and Fyodor were watching everything, Fyodor with a smirk and Sigma was anxious. Velma was doing Velma things, trying to find the rest of the Scooby gang. Tanjiro, Nezuko, Zenitsu, inosuke and the hashira were keeping an eye out for demons. Deku, Bakugou, and Todoroki were preparing to fight with Dabi, Shigaraki and Toga. Goku was trying to figure out which fight he should help out with, as was Saitama. Twilight sparkle was in the corner trying to read a book and ignore all of this. Moxxie, Millie, Loona, and Blitzø were trying to figure out who they were supposed to kill, and Fizzarolli just tagged along with them. Pomni was anxious, N was trying to calm her down. Spiderman and Batman tried breaking up the anime fights, but failed. Douma was trying to eat Elsa. Sans and Chara were battling in the corner. Luffy and Zoro were planning to join a fight (or start one, who knows.) Light and Misa were trying to figure out who's names to write in their death notes. The puppet and Freddy were torturing Springtrap, and Elizabeth was confused. Denji was having a field day, and Power was just existing. Hisoka was thinking not okay things. Ichigo was there (somewhere), as was Shinra and Furina. Sasuke, Naruto and Sasuke were trying to help others battles. Freckle and Rocky were trying to rob a concession stand. Ladybug was trying to help others, and Princess Peach tried to find Mario. Angel dust was flirting with husk, Lucifer was protecting Charlie from the chaos, etc.