Here's where I'm confused: Missy's cyber-control bracelet. She gives it to the Doctor, he tosses it to Danny, Danny uses it to command the Cybermen to fly up with him into the clouds and self-destruct, destroying the clouds and their Cyber-pollen. Okay, so far so good. But in my mind, the cyber-control bracelet should then be destroyed at that point. But no, Danny's still got it in the afterlife (and at this point, which afterlife is he in? - actual Heaven or back in the Nethersphere?) and uses it to communicate with Clara and send back the boy he killed. And the boy arrives in Clara's apartment wearing the cyber-control bracelet, because the Doctor later spots Clara wearing it in the coffee shop and deduces that Danny made it back from the afterlife intact as he had anticipated.
So, all of the Cybermen who self-destructed upon Danny's orders - are their memories and consciousness back in the Nethersphere? And if so, are they in there as Cybermen? (Danny Pink showed up, originally, in the clothes he was wearing when he died. And since they were "wearing" Cyberman bodies when they died this second time....)
Johnathan