At 11:29 in this old gameplay trailer for destiny 1, there is a clip shown of Prince Uldren pointing a gun at our guardian in a earth-looking area and being very aggressive. This clip was never used in the original destiny game, nor was there any other clip of him away from the reef other than in a cutscenes in TTK of the Reef attacking Oryx's fleet. From the grimoire we know that he is rallying up the fallen for some unknown reason. And from the destiny 2 gameplay trailer we can assume we will fight fallen on earth. My theory is that we will see a comeback from this character, maybe this cutscene will finally be shown in-game with different dialogue. Let me know what your crazy theory is! Edit: I understand that the clip is very old and that it has been talked about before now many times. But I am bringing it back up because I feel like it could be relevant again.