#MyDreamCollab
got a few ideas
Honkai impact 3 x Punishing Gray Raven (for the previous era)
Code Geass Lost Stories x Evangelion Battlefields (that would fit rather well)
Touhou LW x Date a live (maybe a touch of chaotic, but I would be interested to see what madness there could be)
Sonic x Megaman (I can't even imagine this one)