I finished a 4M+ last week, and got a key to Vault of the Warden (4M+) this week. I tried it, failed, got a depleted key instead. How am I supposed to go on from here? Given that the system is almost identical to that of GRs (Greater Rifts) in Diablo III, I think we should have a choice of whether to upgrade the key or gain, say, Artifact Power or an extra chest or something like that. Just the first thing that came to mind, might be dumb.