Few of us remember the earlier days of Freak Fortress when you could change class really quick before the round starts, as the boss, and get to use their weapons.
Then the Freak Fortress script went for a fix for that with the "You cannot change classes as the boss" or whatever.
But you sort of can still do it if you spam class changes quick enough, you just don't get your weapons unless you gain one from a rage.
>Mostly posting cuz screenshot.
They're fighting an illusion, a hologram, a figment of their imagination, a detached model.