This challenge requires 2 consoles and 2 copies of RDR.
I launch RDR on both consoles and join either a system link session or a private online session. Once both players are in the same session I use player1 to kill player2 six times which makes player1 a Public Enemy aka Most Wanted. Then I escape the lawmen while maintaining the Public Enemy status. The Most Wanted title will constantly make npc lawmen/bounty hunters attack you every so often. This is where the challenge begins....
Player2 gets a wagon or preferably a Gaptooth Breach stagecoach. Player1 gets into a passenger seat. From this point on Player2 is the protector/hired gun who must escort the Most Wanted player1 around the map. I turn off Player1s TV so that I NEVER know when/if lawmen or bounty hunters are approaching. These attacks can come at a moments notice. Your job as player2 is to keep player1 alive by any means. You can even Roleplay a scenario and create a story surrounding this. For example:
Pretend the Most Wanted (player1) is a witness to a crime and you must keep him alive until the trial. The criminals are trying to silence him, and if he dies, all is lost. Maybe you need to escort Player1 from Escalera (Mexico) to Blackwater (USA). Maybe you need to stop at certain settlements to restock on supplies for the long journey (just to make it more challenging and not rush from point-A to point-B.
Use your imagination and have fun. Thoughts?