I loved s3 so theres not much that I would've changed. When it came to the Pike storyline I would've had a flashback episode that showed how him & Farm Station survived. We also could've seen the immediate aftermath of the fall of Mount Weather in Arkadia. We could've seen Bellamy's resentment of the Grounders more & we could've seen Jasper realize his parents never made it to Earth. He could have nightmares since he later tells Monty he can't sleep at night. We could see the depths of his depression went far beyond Maya; her death was merely the straw that broke the camels back.

The other change I would make would be with Lexa. I would still have Lexa be shot but have her survive. The Grounders could deem her too weak to lead & she could be sent away to heal off screen while we have a new commander rise & the storyline can still play out how it did on the show. Now I think Lexa would never fully abandon her people since she was born to be a leader but if Alycia wasn't available Lexa could've sent a new character as a proxy to speak on her behalf in political matters to try & still have influence over her people. However something would need to happen to the proxy because we need to have the conclave & Octavia has to rise as the leader of Wonkru. The proxy could either die or have there own motives or maybe the Grounders don't listen to them because Lexa is technically no longer the commander & thus the conclave still happens. This idea needs to be fleshed out a bit more but I think it could work. Then Lexa could survive Praimfaya with her nightblood & make her way to the valley like Clarke where they reunite & raise Madi together. Yet there is still the issue of Alycias availability because this would require her to return & what if she could only come back for one or two episodes & not a significant amount of time.