Season 2 Theories and Questiions, spoilers!
Here are my theories and questions regarding season 2:
Milan orchestrated Victor's removal before he knew Victor was a revenant not long after the first flooding... People in the town really trusted him and many went crazy after so much loss looking for answers, believing Victor to have caused the flooding, death of Mrs Costa, etc due to his drawings. Somewhere in Milan's crazy mind, he thought killing Victor would save the town. After Victor is a revenant and living with his adopted father, Milan believes he came back for a divine purpose and so Milan convinces people in the town they will be saved through death and come back right after, and thinks it is all under Victor's thumb somehow. He still believes this up until his conversation with Victor at the police station. It was implied Victor was kept in hiding for 35 years but I think Milan started thinking this way after Victor likely dreamed of the suicide cult in the clearing and came to him to try to stop it from happening once he had come back from the dead. This event probably shook Milan into believing in an eternal return that is free of suffering and tried to "save" those who did not die in the flood. I do wonder what Lucy told him, if anything, relating to being a revenant before his suicide? Considering they knew each other so well...
Serge went crazy from watching his father kill people and from his obvious abusive conviction in achieving his missions. Perhaps he saw zombie revenants in the Forrest as a child eating animal's internal organs and this created psychological damage. Also, his dad killed himself after orchestrating a suicide cult, Serge may have believed all of his victims would be redeemed somehow after death. After seeing that they woke up with no purpose seemed to be when he really started to feel the weight of his actions.
His ending was subtle but so interesting in the tunnel, as he could not allow himself to join the others as he finally faced the horrors of what he had done after seeing the faces of those he had hurt.
No idea what that zombie in the cave was... Super confused there. Is it the same creature that grabbed the camera under water? What exactly is the connection of the water to the revenants? I noticed when Victor woke up after Etienne told he can change things as Julie believes him, the hole the revenants were standing over had suddenly filled with water and the others were gone, implying they found their place back in the water. Also in Camille's coffin, level in the lake lowering as the dead returned. Was this ever explained?
For overall themes, I find the raft guiding the dead as a link to Kharon in Greek mythology (taking them from the land of the living to the dead and vice-versa) Virgil as a link to the guide through hell in Dante's Inferno, and even the fact that Julie decides to call our dear Victor by this name symbolizes that with her he can become just that, a Victor over his circumstances, which is proved in the finale. And of course, the eternal return that we are destined to relive our circumstances infinitely.
Also, the notion of the butterfly effect with the butterfly awakening at the same time as the revenants is a possibile theme. The butterfly that awoke had "victorina stelenes" as its species and was written underneath. Some have speculated that Nathan/Victor are the same person, that he tells Lucy that Nathan cannot cross over on the path and that she needs to look after him as though if the baby crossed over, he could never exist and history would be rewritten. Some clues were given, such as Victor's fearful expression when the baby is left with adoptive parents, that either the child is like him or is him. Also that he may be the zombie in the cave as it wears a similar red sweater/pants. In this case, season 3 would very much be needed to explain ce bordel! I hope that is not the case and that the past/future aren't interlinked that way but maybe a symbol of something else more simple.
I feel like a good amount of questions were answered, enough to gather a general understanding from in the case there is no season 3. Otherwise, it seems as though these answers have peeled away many layers of an onion but a good portion of the nature of the "how" still remain underneath.
Some questions... Where are Victor and Lucy from? How is the water linked to the dead? Who are the other zombies and how long have they been alone in the forest? What pulled Serge into the water last season, the same creature that appeared on the camera? I'm stumped there. What caused the fire those animals ran from? Would love to hear some ideas.