As for how the leasing demon determined whether a target could afford to repay the aura at the start of the lease, Ronin had already figured it out.
It came down to interest and the target's own aura reserves. When the two reached a balance point—the critical threshold—any excess would prompt the leasing demon to forcibly extract the target's own aura to settle the debt.
Ronin's guess was correct.
Milia's profits came entirely from the interest she collected after lending out aura.
When she developed her Nen ability, she made a Vow and Limitation: from the moment she gained the ability to lend out Nen, her own training would no longer increase her natural aura capacity.
However, the interest she earned could continuously raise her aura capacity—and that increase could stack endlessly.
The catch was that anyone borrowing Nen had to fully understand the rules and voluntarily sign the leasing contract.
At the same time, if she wanted to receive interest from the leasing demon, she had to exchange money for points to purchase it.
In other words, from the moment she developed her ability, every cent she earned was converted into points and became a tool for increasing her strength.
That was one of the reasons she made so much money yet cared so deeply about it.
Heavy restrictions brought with them a powerful vow—and with it, limitless potential.
Ronin wasn't the first Nen user she had worked with. Before him, she had already helped propel several others to success.
Now that it was Ronin's turn, Milia was confident he wouldn't refuse to lease aura from her. At least for now, the potential returns far outweighed the risks.
Milia quietly lowered her hand. She had the uneasy feeling that Ronin's gaze kept drifting toward it, intentionally or not.
"Digital calculations are just my personal way of estimating things—not especially precise," she said. "Normally, a Nen user's aura exists in two states inside the body.
"The first is manifest aura—the amount released outside the body. It's the actual amount of aura you can use at a given moment. This upper limit gradually increases with training, and in special situations, it can even burst past that limit.
"As an Enhancer, you should understand this better than anyone. That final punch you threw against Gareg—your manifest aura at that instant clearly exceeded your normal maximum."
Ronin understood exactly what she meant.
That had been Ultra Destruction Fist combined with Sakura Rush.
In that instant, the power Ronin unleashed had far surpassed what he could normally output.
"The second is latent aura," Milia continued patiently. "That's the aura stored within the body. Its upper limit also increases through training.
"I observe your manifest aura and use that to estimate your overall latent aura."
Ronin adopted the posture of a student eager to learn.
"My estimate of the maximum manifest aura you can maintain using Ren is around 700," Milia said. "Multiply that by about ten, and you get your latent aura. Roughly speaking, your total should fall somewhere between 7,000 and 8,000."
A sharp glint of intelligence flashed across her lenses.
"Of course, that's a very rough estimate. If you want a precise calculation, you'd need to fight me—or at least let me see your Ken, and tell me how long you can maintain it."
Not even ten thousand?
Ronin was a little surprised.
Still, the number wasn't low at all—especially for someone who had only awakened Nen a little over a month ago. In fact, it was high.
After all, when Gon cleared Greed Island and later received Biscuit's guidance during the Chimera Ant arc, his aura capacity was only a little over twenty thousand—and that was after a solid period of training with Biscuit.
Ronin having this much aura was entirely due to the forced boost from two pairs of Scarlet Eyes.
Based on this estimate, Milia's own aura capacity was probably around 15,000—or even higher. After all, she likely wouldn't leave herself completely defenseless by lending out every last bit of her aura.
And when calculated this way, it also perfectly matched Ronin's earlier conclusion about the leasing demon's forced repayment rules.
Borrowing double aura for ten minutes required interest of roughly 7,500—almost exactly equal to Ronin's current total latent aura.
If he borrowed double aura from her, Ronin would have around 22,500 aura. With that level, taking on Uvogin would actually be feasible.
Before fusing the second pair of Scarlet Eyes, Ronin's burst aura was probably only around 400. Even with Sakura Rush forcibly boosting it, he'd barely match his current output—yet even then, he'd been able to seriously injure Uvogin.
Now, even a normal punch was on par with that level of power. Once Ultra Destruction Fist and Sakura Rush were combined, the damage would be on a completely different level.
It was doable.
"You haven't been awakened to Nen for very long, have you?" Milia said when Ronin stayed silent, assuming he thought his aura was too low. She offered some encouragement. "With such a short training period, having this much aura already makes you a genius among geniuses.
"Among all the outstanding individuals I've ever seen, your potential and talent are absolutely top-tier."
"Thanks for the compliment," Ronin said as he slid the contract back to her for now. "I will borrow aura from you—but not yet. I'll wait until it's confirmed that the Troupe is sending someone to fight me in the arena."
Milia's contract specified a maximum lease duration of three days.
That meant that within three days of borrowing aura from her, Ronin could use the leased aura at any time by communicating with the leasing demon.
If the borrowed aura wasn't used at all during those three days, the leasing demon would simply collect 5% of the leased aura as interest before leaving.
However, if Ronin actually did that, Milia—having lost a large amount of aura—would likely end up in a dangerous situation. That was why he didn't sign the contract right away.
"Alright," Milia said.
The moment she touched the contract, both it and the floating leasing demon vanished at the same time.
Uvogin's challenge was clearly an invitation to a fight to the death—on the arena stage.
If Uvogin hadn't been to Heaven's Arena before, it would take at least several days for him to reach the 200th floor.
That window was Ronin's final preparation time.
Still, he had to stay cautious and guard against Shalnark making a move from the shadows. Manipulator-type Nen was especially troublesome.
Since Ronin couldn't keep his Sharingan active at all times to monitor his surroundings, it would be even harder to tell whether someone approaching him might be carrying one of Shalnark's antennas.
"Oh, right—if possible, you should give me the Phantom Troupe members' information in advance," Milia added. "That way I can make preparations early and maximize the profits from the arena match."
"You should be careful too," Ronin warned. "If you promote it too early and expose their identities, I'm worried they'll come after you."
"That's true," Milia agreed, not trying to act tough. "A bunch of lawless, bottom-feeding scum like them definitely requires careful handling."
The Phantom Troupe were, after all, A-rank wanted criminals. Combined with Ronin's caution, their strength was clearly no joke.
Milia was confident in herself—but not to the point of arrogance.