>>281804207
We don't know if Poro was as desperate all those years ago as he is now. He was pretty obsessed from the beginning but we don't know when 'he's gone but will come back' turned into 'he isn't coming back' for him.
>>281804241
I don't think so simply because I don't see Nishi skipping a Jackapo mini arc to complete the set.
Baal on the other hand could pull a fast one and show up, 'save' the key for Shakky, playing up his hero reputation just to sneakily take it for himself if the other realm plot gets aborted.
Third option: Narnia, Henri and Iruma. That one seems like the most interesting one of you strip both of them of acting via proxy by sending people on their place.