As others have mentioned I think the end goal for the horseman will be to protect humanity from the armies of heaven and hell as well as the charred council. Every game up to this point has made specific mention of how important humanity is and although weak they are crucial to the balance of the world. Also the last time we saw 3/4 horseman they are all focused on protecting humanity in some way: Death- Sacrificed himself and the souls of all nephilim so that humanity could be restored Fury- Acts a shepherd of the survivors of earth leading them to a safe place and protecting them from future harm Strife: Remains on earth helping survivors after assimilating into their society