Leon Cromwell’s Secret Purpose: Why the Golden City of El Dorado Was Built
If you’re deep into That Time I Got Reincarnated as a Slime lore (yes, I’m talking Light Novel readers and manga completionists), then you already know that Leon Cromwell is way more than the icy villain we first met. On the surface, he’s the Demon Lord who abandoned Shizue Izawa and casually summoned children into a world that couldn’t sustain them. But dig into the canon, and the truth hits differently.
Leon isn’t chasing domination. He isn’t drunk on power. He built the Golden City of El Dorado for one reason — and one reason only: Chloe Aubert.
The Biggest Plot Twist in Tensura: El Dorado Was Never About Wealth
Let’s clear something up. El Dorado isn’t just some flashy Demon Lord capital dripping in gold and platinum. It’s not Leon flexing his ego. It’s not just a fortress to intimidate the Octagram. It’s a continent-scale magical apparatus.
The entire city functions as an enormous summoning framework — a hyper-advanced magical engine designed to reach across dimensions. That detail completely recontextualizes everything Leon does.
When Leon and Chloe were separated during their original transportation to the Central World, he didn’t move on. He didn’t accept fate. He spent centuries trying to correct a cosmic error. And El Dorado? That’s the culmination of that obsession.
How El Dorado Actually Works (And Why It’s Genius)
From a magical engineering standpoint, El Dorado might be the most insane structure in Tensura. It serves multiple layered purposes:
- A Giant Magic Circle: The entire infrastructure is built as one massive summoning formation. Streets, architecture, and ley lines are all part of the system.
- Stabilization Platform: High-tier summoning magic is volatile, and El Dorado provides the mana density and spatial stabilization required.
- Filtering System: Leon used incomplete summoning methods to increase the probability of eventually reaching Chloe’s signature.
- Controlled Environment: A place where summoned Otherworlders could survive and integrate.
This is where the fandom debate gets heated. Because yes — Leon summoned children. But here’s the uncomfortable nuance: most summoned individuals would die from magicule poisoning. So what did Leon do? He created a system to manage and protect them.
The Sanctuary Nobody Talks About
One thing that often gets lost in community debates is that El Dorado became a haven for Otherworlders. Leon didn’t just toss summoned kids aside. He built infrastructure for education, social integration, protection, resource allocation, and long-term survival.
Was it morally clean? Absolutely not. Was it reckless? Definitely. But was it random cruelty? No. Leon was running probability experiments on fate itself — and trying to minimize casualties within the rules of a broken system.
Why Leon Became a Demon Lord (It Was Strategic, Not Ego)
Joining the Octagram wasn’t about prestige. It was insulation. By becoming a Demon Lord, Leon secured political deterrence, territorial control, resource stability, and operational freedom.
| Strategic Move | Purpose |
|---|---|
| Demon Lord Title | Political deterrence and autonomy |
| Territory Control | Isolation for summoning experiments |
| Resource Monopoly | Funding large-scale magical research |
| Volcano Base | Access to rare metals for magical infrastructure |
El Dorado sits on a volcanic region rich in gold and platinum, both crucial for high-level magic circuits. Leon even traded with powerful nations to sustain his research network. This isn’t the behavior of a tyrant. It’s the behavior of someone running a centuries-long rescue operation.
The Kazaream Factor
Leon didn’t start with El Dorado. He originally took territory from the former Demon Lord Kazaream. After that conflict, Leon realized he needed total isolation and complete structural control over his environment. So he created an artificial continent designed entirely around spatial magic and summoning theory.
That’s not villain energy. That’s obsessive genius energy.
Why Did Yuuki Kagurazaka Kill Mariabell Rosso? The Truth Behind the Ultimate Betrayal in Tensura
Shizue and Ifrit: The Scene That Changed Everything
The Shizu situation is the emotional core of Leon’s reputation. He bonded her with Ifrit. To most viewers early on, that looked monstrous. But later revelations flip the narrative completely.
Without that bond, Shizue would have died from magicule overload — the same fate that kills many summoned children. Leon’s flaw isn’t malice. It’s emotional illiteracy. He doesn’t explain himself. He doesn’t soften the blow. He executes solutions clinically, and that makes him look heartless. But intent matters.
The Misunderstood Hero Archetype
Leon Cromwell might be one of the most misunderstood characters in modern isekai. He fits into a rare archetype: The Hero Who Became the Villain in Public Perception.
Unlike Rimuru, who builds bonds and diplomacy, Leon isolates himself. He weaponizes fear. He embraces the Demon Lord image because it keeps interference away from his objective. And that objective never changes: find Chloe, even if it takes centuries, even if history paints him as a monster.
Final Thoughts: El Dorado Was a Promise, Not a Throne
Leon Cromwell didn’t build El Dorado to rule the world. He built it to correct a mistake of fate. Every summoned child, every political move, every resource deal, and every cold decision was part of a centuries-long attempt to bring Chloe Aubert back.
You don’t have to agree with his methods. You don’t have to forgive him. But calling him a simple antagonist misses the point entirely. In a series full of reincarnated slimes, evolving monsters, and political masterminds, Leon might be the most human character of them all. And that’s what makes El Dorado shine.








