I've been reading the Re zero novels for quite a while now, and since I'm caught up with the story, there's one question that keeps coming back to me: who is actually the main or final antagonist of Re zero?
Many people would immediately answer Satella, or more specifically the Witch of Envy. However, I personally don't think she fits the role of the final antagonist. From what we've learned so far, Satella was forced to take in the Witch Factor of Envy, which eventually created the Witch of Envy personality. I think she's more of a victim who needs saving than anything else. While she is undoubtedly one of the main reasons why many of the events of the story happened and remains one of the ultimate goals of the narrative, I don't see her as the true final enemy. She may be one of the final obstacles, but not the final antagonist itself.
If we set Satella aside, there are two major candidates left in my opinion: Pandora and one other person.
Pandora is the first obvious possibility. She appears to be the current leader of the Witch Cult and has been connected to several of the most important tragedies in the story. She is responsible for Petelgeuse's downfall, played a major role in the events that led to the Astrea family's current situation, and in Arc 6 it is implied that she may be observing events through the birds seen around the world. We still know very little about her motives, goals, and true nature, making it difficult to draw any definitive conclusions. However, based on everything we've seen so far, there is definitely a possibility that she is being set up as the final antagonist.
That leaves one final person, echidna, who I personally believe is the most likely candidate.
My first reason is that a surprising number of the major conflicts in the story can be traced back to her actions, either directly or indirectly.
In Arcs 1 through 4, Roswaal's actions are guided by the Tome of Wisdom, a copy created from Echidna's Authority, and much of the suffering in those arcs happens because of his desire to fulfill his plans and eventually bring her back to life.
In Arc 5, the Sin Archbishops attack Priestella following the guidance of their Gospels, which are themselves imperfect copies of the Tome of Wisdom.
Arc 6 can also be connected to her influence. In Arc 9, we learn that Echidna somehow tricked Od Laguna and forced it to create the Books of the Dead. Those same Books of the Dead played a crucial role in Subaru's memory loss during Arc 6 due to Louis Arneb's actions.
The connection becomes even more obvious in Arcs 7 and 8 through Sphinx. Sphinx was one of Echidna's failed experiments in her pursuit of immortality. After abandoning her creation without destroying it, the consequences of that decision would eventually lead to major conflicts hundreds of years later, including the civil war in Lugunica and later the events in Vollachia.
Arc 9 also places a major focus on Aldebaran, who is directly connected to Echidna as her student.
Because of all this, it feels as though Echidna's influence is present throughout almost every era of the story. Even after her death, many of the world's greatest conflicts continue to originate from the plans, creations, and experiments she left behind.
My second reason is more theoretical and relates to what may become the final ideological conflict of the series.
We know that Echidna genuinely wanted to save the world. According to what we've learned, she was unable to accomplish that goal alone until Flugel and his group appeared. However, at some point they seem to have separated due to differences in ideology and in how they wanted to solve the world's problems, something hinted at in the side story "No Stella, No Life."
My personal theory is that Echidna wanted to kill Satella, while Flugel wanted to save her.
We know that Echidna is willing to sacrifice countless lives if it means achieving her objective. Her flashback in the web novel makes that much clear.
The problem is that Subaru has already sworn to save Satella.
If saving Satella truly puts the world at risk, then I could easily see Echidna opposing Subaru until the very end. To her, the world is worth more than a single person. It is even possible that many of the events unfolding today are the result of plans she put in motion 400 years ago. After all, her flashback reveals that she was willing to designate countless lives as sacrifices in pursuit of her objective and the final one may be satella herself.
Subaru, on the other hand, represents the complete opposite philosophy. The people he cares about are worth more than the world itself. He would sacrifice himself over and over again if it meant saving them.
That is why I think Echidna is currently the most likely final antagonist of Re zero. Not because she is necessarily evil, but because her ideals may ultimately be incompatible with Subaru's.
I'd love to hear your thoughts. Do you agree, disagree, or do you have another candidate in mind? Feel free to share your theories or point out anything I may have missed.