I'm sure many people have said this, whether it's denial or wishful thinking, but what I propose has evidence. Look at the [i]sealed ahamkara grasps[/i] for the hunter. It's lore tab reads: "...A pair of truths and a single falsehood upon the Bearer we shall impart. Brother, ally once more, sends his regards. Dreamer, awakened, the Bearer shall meet. Light fades, deep within the Prison." The brother is Osiris, (warlocks often refer to each other as brother/sister, especially the cult of Osiris) who has returned and redeemed himself thus once again becoming an ally. The dreamer is either nokris/xol awoken from inside the ice, or it's Rasputin. I think it's more likely nokris & xol as Rasputin didn't really have a dream. The light in the prison is obviously cayde's death. [b]However[/b] one of these are false. We definitely know that Osiris came back, and the hive/Rasputin definitely woke up, that leaves... Of course this isn't definitive proof, seeing as these three phrases from the ahamkara could be taken in different ways, for example the dreamer could have nothing to do with the warmind expansion and it is in fact the falsehood. But I think it's fair to say this is a decent argument for cayde's survival.