Among all of Rimuru Tempest’s subordinates, Diablo’s recruitment of the Demoness Trio was one of the most impressive moments in That Time I Got Reincarnated as a Slime.
Unlike ordinary monsters who joined Tempest because they admired Rimuru’s strength or leadership, the Demoness Trio were ancient beings who had existed since the beginning of the world.
Testarossa, Carrera, and Ultima were Primordial Demons beings with immense power, pride, and thousands of years of experience.
They were not the type of opponents who would simply accept someone’s orders. For Diablo to recruit them, he had to prove that he stood above them.
Why Diablo Chose the Demoness Trio
After becoming Rimuru’s subordinate, Diablo searched for powerful allies who could serve his master, instead of choosing ordinary demons, he went directly to the Demon Realm and targeted three of the strongest beings he knew: the Demoness Trio.
However, recruiting them was not simple, Primordial Demons were extremely arrogant and independent.
They did not recognize authority unless someone proved they were worthy of respect.
Because of this, Diablo understood that each of them required a different approach.
Carrera: The Demon Who Understood Only Strength
The first challenge Diablo faced was Carrera.
Carrera was known for her overwhelming destructive power and her aggressive personality.
She valued strength above everything else, meaning that words alone would never convince her to follow someone.
Diablo understood this perfectly.
Instead of negotiating, he completely overwhelmed her with his power.
He showed no hesitation and was merciless during their confrontation because he knew that Carrera would only acknowledge someone who could defeat her.
By proving that he was far above her level, Diablo broke through Carrera’s pride and gained her recognition.
Ultima: A Battle Diablo Had Already Won
Ultima presented a different challenge.
Unlike Carrera, Ultima was more playful and deceptive, but she was still an extremely dangerous Primordial Demon.
However, Diablo already exposed and challenged her before during the Kingdom of Raja incident.
During their battle, Diablo completely controlled the situation, every attack Ultima launched was neutralized, and she was unable to gain any advantage against him.
Eventually, the strain became too much, her magicules were exhausted, her body began to collapse, and she was forced to retreat.
This battle demonstrated that even another Primordial Demon could not easily challenge Diablo.
Testarossa: The Primordial Diablo Treated Differently
However, Testarossa was different.
Before meeting her, Diablo did not simply walk into the confrontation expecting an easy victory.
He carefully considered how he should approach her because he knew that Testarossa would not fall into line as easily as the other two.
This reaction revealed something important.
Diablo did not view Testarossa as someone he could casually dominate. He understood that she was powerful enough to potentially become a serious threat under the right circumstances.
Her danger did not come only from her strength.
It came from her intelligence.
Why Testarossa Was So Dangerous
What separated Testarossa from the other Demoness Trio members was her ability to combine power with strategy.
Carrera relied heavily on overwhelming destruction, while Ultima enjoyed deception and cruelty. Testarossa, however, was much more calculated.
She analyzed situations carefully, manipulated opponents, and planned several steps ahead.
She was not someone who would simply charge into battle. Instead, she searched for the most efficient way to achieve victory.
This made her dangerous even against someone like Diablo.
A fight against Testarossa was not only a battle of strength—it was a battle of intelligence.
Diablo and Testarossa: Strength vs Political Intelligence
Although Diablo remained superior in direct combat, Testarossa possessed a different type of talent.
When it came to politics and diplomacy, Testarossa was one of the most capable characters in Tempest. She understood negotiations, manipulation, and international relations better than almost anyone.
Diablo’s greatest strength was his absolute loyalty and ability to execute Rimuru’s wishes. Testarossa’s strength was controlling situations through intelligence and influence.
This was why their roles in Tempest were different:
- Diablo became Rimuru’s strongest enforcer and most loyal servant.
- Testarossa became one of Tempest’s greatest political weapons.
Their strengths complemented each other rather than competing against each other.
Final Thoughts
Diablo’s recruitment of the Demoness Trio showed why he was feared even among the Primordial Demons.
Carrera and Ultima were brought into submission through direct confrontation and Diablo proved his superiority by overwhelming them with his strength.
Testarossa, however, was different, she was not simply another powerful demon who could be forced to obey.
Diablo recognized that she possessed the strength, intelligence, and pride to require a more careful approach.
Her recruitment showed that among the Demoness Trio, Testarossa was dangerous not only because of her power but also because of her ability to think and manipulate situations.
In the end, Diablo did not simply gain three powerful subordinates, he recruited three ancient monsters who could have remained his rivals and transformed them into some of Rimuru Tempest’s most valuable allies.
