I've completed nightfall normal campaign the other day and decided to give the legend difficulty a shot (replaying every mission on legend). I finished it just now and I'm 101% sure that all missions have been completed on legend difficulty since the red skull in the mission mods is not there anymore and I got the triumphs for the completion. However, when I talked to Nimbus, it just went to the default NPC page, he didn't offer any exotics. Am I missing something?