I don’t normally share Anti theories but I’m seriously excited haha. My take on this is that Anti is a computer virus (pretty common theory!) who somehow got into Jack’s head and sometimes controls him etc. Anti tried to murder Jack back in October, infected his show at PAX, and I believe somehow transferred into Mark’s computers while Jack was in LA, hence how he’s encountering Dark!
The part was my favourite; it perfectly captures how Anti is manic and almost childish in that he giggles. When facing danger, he just laughs in its face. IMO, I think Anti is younger and more dangerous than Dark. He takes danger and death as a joke, because it can’t hurt him. He’s not scared of anything.
To him, the world is one big, fun video game in which he can’t die.