Cayde-6 returns and the game uses him precisely — not as a resurrection of the thing that was taken but as the proof that the thing that was taken mattered. His presence in the Pale Heart is not fanservice, or not only fanservice. It is the game's argument that the Light's failure is survivable, that what the Light built in people persists even when the source is gone, that hope is a behavior rather than a condition.

What you do when the Light fails is keep moving. Keep the fireteam together. Complete the objective. The session demonstrates this not rhetorically but mechanically — the game puts you in situations where the resources the Light normally provides are unavailable and asks what you have left. The answer is: the choices you made before the failure. That is always the answer.