The act of John Rambo embarking on what typically is known as a rampage. However, that definition only applies to everyone who is not John Rambo. If this ultimate male specimen ever decides to "rampage," the condition is then upgraded to a "Rambage."
<Dude1> Did you see that Rambage? It was sooooo much better than that other guy's rampage.
<Dude2> Dude, that's because he's Rambo. Only Rambo could do that.