My buddy and I were just talking about that the other day. We thought it would be cool if the hive began to invade and make their way through the city below the tower. The entire siege would last from a day to a week and would require a good majority of the community to help fend off the invasion. Each mission would require you to protect an area of the city kind of like the Halo firefight. If you succeed then the guardians can hold that area but if you fail then the hive will own that area. If too many guardians fail to hold their ground the hive will eventually make their way to the tower where the guardians will make one final effort to defend their home. Three man fireteams turn into six as the hordes becoming stronger and more relentless. The community has to give it their all or risk losing the tower. Failure means no more bounties, Cryptarch, Vanguard, or strikes until the tower is retaken. If you succeed in defending or retaking the tower the missions take a more offensive stance as you now have to retake the areas you failed to hold until the hive is finally pushed back. Think about how epic it would be, you'd round up your buddies in a fireteam and the Speaker would send you to a part of the city that must be defended like a hospital or street. There you would fend off waves of hive, ammo running dangerously low, you desperately try not to be overrun. Suddenly, when you think you have the street secured hundreds of thrall come sprinting around the corner. You and your team take position and unload whatever bullets you have left. Your Warlock unleashes his ability and blows away the front chunk of the wave, only for those thrall to be replaced by fifty more. The hunter and titan launch a couple salvos from their launcher, temporarily pushing the flood of enemies back. One by one each of you run out of bullets, yet the thralls are still pouring down the street screaming in defiant rage. At first it's only the fastest thralls that break the line, a few, but they are quickly dealt with by the knife of the hunter. But the number of thralls breaking the line begins to swell and you quickly find yourself surrounded. The hunter makes a desperate attack and unleashes his blade dancing ability, only to be swallowed by the mass. The Warlock is consumed by the horde shortly after. The crowd has thinned and with the last of his strength the Titan slams his mighty fists into the ground, disintegrating the remaining thrall. You're fire team has successfully secured the street, barely. A couple streets over another fireteam was not so lucky. They were quickly overrun and failed to protect the civilian evac point. Thousands of citizens are killed at the site. More will die now that there is no place for evacuation. Once those guardians have recovered from their engagement they will be sent back out to retake the evac point. However the enemy will now be stronger and will have had time to prepared defenses. Players who prefer or have to play solo can either hold points on a smaller scale OR run reconnaissance on areas held by the Hive. Searching for generals and princes, that once identified can late be assassinated by a strike team or lone wolf. At the end of it all the players and fireteams who held or retook the most points are awarded with emblems, shaders, perhaps ascendant shards and energy. Everyone else is given complimentary tacos and a pat on the back from the Speaker.