Both heroes are at their strongest and are trying to kill.
Alright kids we are going back to Civil War.
Captain America is about to finish off ironman like in the major story and there are no civilians or other heroes to stop him this time. As a last resort stark calls in his partner, and War machine flies in and tries to reason with captain America but he is to blood drunk to listen. Jim flies into the captain to stop him, while this is going on a flock of birds fly over head and using his ability to see through their eyes The Falcon, notices his partner Captain America in a fight with Warmachine and ironman. The Falcon knowing that this is another escalation of the civil war goes to save his friend and stop the other heroes form doing the unthinkable.
The Falcon lands onto the battlefield watching his friend struggle with warmachine, not knowing him and warmachine have the the same motive...initially. Falcon fires a warning blast at warmachine causing him to release steve rodgers, and seeing his friend get shot at causes tony stark to lunge at the falcon. Cap prepares to throw his shield at stark, so warmachine makes the sacrifice and blasts Captain America into oblivion. Falcon distraught flies ironman into the air and then crashes him down crushing the weakened hero. Now it is The Falcon Vs Warmachine two heroes who have just killed each others bestfriends over a war no one wanted. It is to late to apologies and one must die.