A crossover between The Sandman (2022) and Inception (2010) would be interesting because Inception's dreaming sharing technology would have developed during Dream's captivity, so his return to the Dreaming would almost certainly have affected its use.
And building back earlier it's possible that Dream's captivity and the side effects there of, aka the sleepy sickness and such, may have inspired humanity towards a greater study of sleep and dreams that then formed the eventual base of knowledge necessary for the creation of dream sharing technology.
Plus... what would happen if someone tried to use a PASIV Device on a Dream or Nightmare pretending at humanity in the the Waking World? Would Somnacin even affect them? And if it does (assuming that the affect isn't something like 'instantly banishes them back to the Dreaming' - useful as that might be) what would trying to dream share with one of Dream's creations do to a human? What would it do to the Dream/Nightmare? And this was tried both during and after Dream's imprisonment, would the affects differ?
