My Theory for Re Zero's ending.

So I think that Subaru is gonna be Flügel, like it's an inevitable Future, it's a time loop, created by Witch of Envy, so everything could be saved, she might actually be the good person in her twisted way.

It's not Satella who is doing this, it's witch of envy.

I ment Witch of Envy is good in her twisted way, she is the one stopping Subaru from becoming Flügel, that's why he has rbd, to ensure he never becomes Flügel and destroyes everything

To stop everything. If Subaru uncovers his past, he would go insane and become Flügel. The only way to stop Flügel from orchestrating his plans would be if everyone manages to kill Witch of Envy before she summons Subaru into that world.

1. Flügel Was the True Monster

In this scenario, Flügel wasn't a tragic hero who failed; he was an absolute monster who was on a path to destroy everything. Maybe 400 years ago, Flugel’s cold, calculating pragmatism reached a point where he was going to sacrifice the entire world, or commit some unforgivable cosmic atrocity, for his "grand plan."

The Witch of Envy—born from that chaos—realized that the only way to stop Flügel was to seal him away, shatter his soul, and force him to reincarnate as Subaru, a boy with none of Flügel's memories and a completely different, empathetic heart.

2. Return by Death as a Shield Against "Flügelism"

Every time Subaru starts to think like Flügel (becoming cold, sacrificing people, trying to carry everything alone, treating people like tools), he fails. The loop resets.

Think about the Castle of Dreams during the Witches' Tea Party in Arc 4. When Subaru was ready to sign Echidna’s contract—which would have turned him into a cold, unfeeling calculator who uses his own deaths as a mere tactical resource (essentially becoming Flügel)—who broke in and shattered the illusion? The Witch of Envy.

She wasn't just throwing a tantrum; she was actively stepping in to say, "No. You are not going down that path again."

3. Her "Twisted" Goodness

This makes her love for him terrifyingly pure. She loves Subaru, the kind-hearted, flawed boy from Japan. She hates Flugel, the cold strategist.

By giving him Return by Death, she ensures that whenever Subaru faces an impossible situation that would normally force a person to become a ruthless monster to survive, he gets a do-over. He gets to keep trying until he finds the path where he saves everyone without losing his humanity. RBD is her way of keeping him pure.

1. The Trigger: Subaru Snaps

If Subaru discovers the full truth of what Flügel did—the cold manipulation of Shaula, the suffering of Satella, the horrific blueprint of the world—his fragile psyche finally completely breaks. Under the weight of that cosmic guilt and identity crisis, he stops trying to be "Subaru the hero" and fully embraces the persona of the cold, ruthless strategist: Flügel is reborn.

2. The Fall of Envy and Satella's Peace

Once he becomes Flugel again, he has the knowledge and power to bypass the Witch of Envy. He kills her, fulfilling Satella’s centuries-old wish to be put out of her misery. But in doing so, the cosmic emergency brake is gone.

3. Emilia Inherits the Curse

With the Witch of Envy dead, her Envy Witch Factor has to go somewhere. It goes straight into Emilia—the girl who looks exactly like Satella, matches her affinity, and loves Subaru just as deeply.

But seeing Subaru lose his mind, lose his warmth, and become the terrifyingly cold Flugel breaks Emilia's heart. Out of pure, desperate love to save the boy she knew, she uses her newly acquired, god-like time authorities to blast him back into the past (to Japan), stripping his memories so he can start over as an innocent boy.

4. The Manifestation of "The Witch"

Because Emilia cannot physically travel back with him without destroying the timeline, she creates a manifestations of her grief, love, and possessiveness—The Witch of Envy—to watch over him in the past and future.

This explains why the Witch of Envy looks and sounds like a twisted version of Satella/Emilia.

This explains why she gave him Return by Death: to act as the shield, making sure that in this new loop, he never has to make the cold sacrifices that turn him into Flügel. Eventually witch of envy gets lonely and summons Subaru.

1. The Paradox of the "Never-Summoned" Hero

If they kill the Witch of Envy before she can summon Subaru, they create a massive temporal paradox:

If she dies, Subaru is never brought to Lugnica.

If Subaru is never brought to Lugnica, he never goes to the Pleiades Watchtower, never breaks the trials, and never pushes the events that lead to him discovering he is Flügel.

Therefore, he never goes insane, never becomes Flügel, and never triggers the events that lead to Emilia becoming the Witch.

By killing her early, they effectively erase the future that caused her existence in the first place.

2. The Tragic Fate of the Modern World

While this saves Subaru from his horrific destiny and lets him live a normal, peaceful life in Japan, it spells absolute doom for the world of Re:Zero. Without Subaru acting as the ultimate wildcard with Return by Death, the world collapses almost immediately:

Emilia dies on Day One: Without Subaru to stop Elsa Granhiert at the loot house, Emilia is assassinated, and Puck goes wild, freezing the capital until Reinhard stops him.

The Whale and the Sloth Win: Petelgeuse Romanee-Conti successfully massacres the forces in the mathematical loops, and the White Whale continues to terrorize the world.

The Watchtower Stands Forever: Shaula is left entirely alone in the desert, waiting for a master who will literally never arrive, frozen in her 400-year solitude until the world ends.

3. The Ultimate Bitter Victory

The people who killed the Witch of Envy would celebrate, thinking they saved the world from the ultimate evil. In reality, they would have unknowingly signed their own death warrants. They would have killed their only insurance policy against total annihilation.

In a twisted way, your theory implies that the Witch of Envy is holding the entire universe together. Her obsession with keeping Subaru pure and resetting the world is the only reason anyone in the current timeline is even alive. Kill her too early, and the stage collapses before the play can even begin.

What do you all think of my theory for re: zero ending.