Since the MoS/BvS/JL story thread has now been pretty much burned, I sometimes think about what would or could have been… in no particular order…
Jeremy Irons’ Alfred defending Wayne Manor/Manor Base in hand-to-hand combat. You know it was gonna happen.
Cyborg’s extra limbs and faceplate in combat mode during the Knightmare timeline.
Darkseid’s omega beams tearing through buildings and landscapes at the climax of Justice League Part 2.
Knightmare Flash time-travelling and delivering the message to Bruce during BvS.
Batman delivering the killing blow to Darkseid and dying in the process. This would almost certainly have been a flipped version of the BvS Doomsday fight with Batman, instead of Superman, retrieving the weapon and dying at the climax.
Superman carrying a dying/dead Batman’s broken body at the end of the fight.
The full authentic version of Cyborg’s birth that we only saw a snippet of in BvS.
A return of Russel Crowe as Jor-El, and/or maybe even Michael Shannon as Zod.
The League going cosmic in Justice League Part 2, with the Flying Fox being upgraded for spaceflight.
The green lanterns joining the fight against Darkseid.
Batman using his wits, strength and mastering of technology to maintain a parity of ability with his meta-human partners.