Maybe he turns into the Kefka of FF14 and becomes the final boss of 4.0.
I always picture Elidibus as the antagonist type who is performing the wrong things for the right reasons. I am still getting this vibe that we may learn that he is right but we have to stop him because his methods are wrong type of ending for when we finally defeat Elidibus for good in the Storyline then with the truth learned the WoL takes on handing the Truth the right way.
However, this is just me mumballing since a part of me still believe Zodiark is a alternate personailty of Hydaelyn when the Mother Crystal is full of Darkness but when she is full of Light she is Hydaelyn. One side is benevolent and wish for the world where the people is in comfort before it is fully consumed by her thus "becoming one with the Mother Crystal" while another is more agressive, destructive, and wish to devour the world fast not caring about who is suffering as long "he" gets to devour all Aether in the world.
I actually think we won't get a Victory in 3.5 but instead we end 3.X storyline with another defeat but this time the Warrior of Light actually is killed in 3.5/3.55 by the hands of the Warriors of Darkness and during the WoL's Death state we finally get to see the Full Truth Elidibus speaks about through echo visions (AKA a very long cutscene you may need to bring popcorn and a drink to watch) and once the vision ends the WoL wakes up to follow events that set the stage for entering 4.0 area.
