It seems we are close to this but not quite...

Seeing Apocalypse use random people like Banshee and Unus or even Rictor when he should logically still have followers or a team.

Apocalypse - shouldn't he have access to some of his ex-Horsemen? what about some of the Dark Riders? still would seem less awkward then some of the X-Men following him now.

Exodus - should be tons of Acolytes on Krakoa waiting to be used?

Magneto - well there's Lorna and whatever she's doing. he's had plenty of followers throughout the years as well. maybe Pietro if that situation ever gets fixed....

Sinister - there's the current Hellions and the legacy Marauders. how about getting to see our old Nasty Boys again? I still have a soft spot for them after X-Men the animated series.

Mystique - obviously there's Brotherhood members who are still around like Toad, Blob, and Pyro. Avalanche has to be around. maybe Super Sabre or Stonewall go brought back? Crimson Commando? give Phantazia something to do.

Shaw - assuming he sticks around obviously there's Leland? any other ex Inner Circle people. maybe would be cool for some of Shinobi's old allies to pop back up. even the Upstarts.

Emma - the original Hellions and Gen X kids?

Kate - well she has her current Marauders.

Jean/Storm/Kurt - there's too many X-Men here. Jean or Storm could be it. It'd be really cool to have Sam/Berto swap in and let the New Mutants era have a representative. the Morlocks really need a voice too after all they've been through. I guess Storm could be it but I think Callisto should get a seat.