As long as it was fully selectable and ENTIRELY voluntary, could see this being a better PVP option than the Crucible ever was. However, with the way things are now in Destiny, I think there are much bigger issues that have to be ironed out before this could even begin to be implemented. I would personally want it to have a solid foundation of story though. Why shouldn't guardians be able to rely upon one another when outside the city? Yes, there are uncommon instances in which an individual goes rogue, like Dredgen Yor. There may even be a group of guardians that are unpredictable and even dangerous when out in the wild. -But every guardian? It makes sense to me that guardians would rely on each other's strength when away from the city, rather than turn on each other. Especially when considering the hurdles faced in public events, or faced with another significant PVE enemy like what you describe here. Can you imagine trying to bring down a fallen walker, while also having to keep a really close eye on that gunslinger with the sniper rifle over there? And a Defender throws his bubble up to block the blast if the walker's main gun. There are orbs of light and buffs that you would gain from the Ward... But you see that Helm of Saint-14 that he has on, and your not sure whether or not entering the bubble would be a good idea... I am not saying that there would be a complete breakdown of teamwork, but it would definitely strain cooperation.