Called something like Hardcore Crossfire, when you enter this mode you are randomly chosen a class (or people can choose, but still only one per class), based on who else is currently playing. Only one person per class allowed on each team. Players can switch classes with each other in the spawn room if they want, but it would kill them.
And what's hardcore about this? Sounds more like ireallyreallyhateassassinsanddontwanttheminmygame crossfire.
I love assassins, i am one. I just want a gametype where each team only gets 1 of each class. I guess we could call it something else lol