Facepunch, looking to move up in the world, arrived on /co/ve and, seeing that there was opportunity to be found, quickly invited his associate Crotch Rocket to come join him. Together they formed a mercenary group, working for whoever paid them.
The group didn't actually have a name until after Arms guy joined and Facepunch discovered they could "combine" to form a "giant robot".
Face Punch is laying on the ground, beaten, Crotch Rock-it equally beaten, Arms guy is still standing, not that beaten.And so the name Full Body Beat Down came to be.
Face Punch: "Damn, these heroes are tough, we'll have to use... *that*!"
Crotch Rock-it: "What? Since when have you been hot blooded?"
Arms guy: [Floating question mark above his head]
Face Punch: "Just be ready to get on Rock's shoulders, Arms."
Running and positioning
Face Punch: "NOW! UNION!"
Somehow the "transformation" sequence was so stupid and silly that it caused everyone else to pause, giving them a chance to get some hits in before blasting off.
Somehow they actually are stronger like this.
Usually they take jobs as hired distractions causing civic disturbances or robbing local stores so other villains can commit more sinister crimes. They will also happily accept contracts to fight other villains if the pay is good.
Another upstart going by Ear Shot, a young man with guns for ears, wants to join their group, but Face Punch won't let him because he believes Ear Shot wants to usurp his position as head. Ear Shot is undeterred by this rejection.
They consider Fistress as something of an arch nemesis.
Their body part theme was coincidental.