Yeah they cosplaying, like if you look closely you can see Kabuto on the right of page 8 and qiqi from genshin on page 9 + you can see the big bazookas lady from resident evil on page 14 and detective's costume idk why but it's giving me hollow vibes
Well you have to consider that they said that he broke just the first level of the seal he put on himself so maybe when he removes the other levels he will be able to do so.