The reason the Marines had been able to dominate the seas for so many years was because they possessed a complete and systematic military structure.
Among those systems, their medical infrastructure was especially advanced.
Just comparing Marines and pirates revealed the difference clearly.
Take the same era's legends, for example.
In his old age, Whitebeard was riddled with illnesses and had to rely on IV drips to stay alive.
Meanwhile, Golden Lion Shiki had a ship's wheel stuck in his head for over twenty years and still hadn't managed to remove it.
On the Marine side, things were very different.
Garp ate senbei and donuts all day without worrying about cholesterol or blood pressure.
Sengoku even had the leisure to raise a pet goat.
Neither of them seemed to suffer from any major illnesses.
Zephyr was the unlucky exception.
He had developed asthma and lost an arm, which caused a noticeable drop in his combat power.
But even then, when he had still been an active Marine, the organization had planned to develop a mechanical arm for him.
Compared to pirates, the Marines' "after-service care" and retirement benefits were on an entirely different level.
If Shiki saw it, he'd probably be jealous to death.
And at this moment, Diarmuid was personally experiencing that level of treatment.
This warship was worthy of being an Admiral's vessel—its facilities were excellent.
The medical officer treating him was actually a healing-type Devil Fruit user.
After a round of treatment, Diarmuid was already mostly healed.
All he needed now was a couple of days of rest.
Lying in his hospital bed, Diarmuid still felt like the whole situation was somewhat unreal.
Everything had gone too smoothly.
The assessment had been far too casual.
Before he could even fully process it, he had already passed?
Thinking about it, he glanced at the sword placed beside his bed.
Nagasone Kotetsu.
He had gone to great lengths to obtain this Great Grade Blade in order to increase his chances.
In the end, it hadn't played much of a role at all.
And he had even offended the Donquixote Family in the process.
Still, Diarmuid didn't regret it.
One of his personal principles had always been:
Prepare as thoroughly as possible before anything happens.
At the time, he had no idea what the Officer Training Camp assessment would involve.
Taking extra measures beforehand had been completely reasonable.
As for Doflamingo?
Whatever.
If he had the guts, he could come to Marineford and cause trouble.
Besides, even if Diarmuid wasn't the type of swordsman obsessed with swordsmanship, having a Great Grade Blade at his side was still a good thing.
No matter how he looked at it—
It was worth it.
While Diarmuid was lost in these thoughts, the door to his hospital room quietly opened a crack.
Hearing the noise, Diarmuid assumed that either Zephyr or Sengoku had come to visit.
He immediately pulled himself together and even prepared to get out of bed to greet them.
In truth, Diarmuid had always been realistic about his position.
Just because he was a transmigrator didn't mean he thought he was superior to the natives of this world.
Strength and status determined how one should behave.
If he were the strongest man in the world, then of course he could lie there and wait for others to greet him.
But he wasn't.
So when facing stronger figures, showing respect was only natural.
Especially when those people might soon become his superiors.
However—
Just as he was about to get out of bed, a small head poked through the doorway.
It was a blond kid.
Diarmuid froze.
The two of them stared at each other across the room for a moment.
Then the child, looking somewhat shy, slowly squeezed through the door and entered.
"Who are you?" Diarmuid asked, puzzled.
His tone was fairly gentle.
After all, he had no idea who the kid might be.
For all he knew, he might be some noble's child—or even Sengoku or Zephyr's illegitimate son.
The boy looked extremely shy.
Without saying anything, he walked up to the bedside and awkwardly extended both hands forward.
In his palms was a bright red apple.
It looked like he wanted Diarmuid to accept it.
Diarmuid was even more confused now.
What was this kid doing?
Still, after thinking for a moment, he accepted the apple.
"Thank you," he said softly.
Only then did the boy seem to relax, a small smile appearing on his face.
Holding the apple, Diarmuid glanced at him again.
Seeing the boy's expectant expression, he sighed slightly and took a bite.
After all, this was a warship commanded by two Admirals.
There was no way anything dangerous would happen here.
The moment he took that bite, the boy finally spoke.
"Rosinante."
"Rosinante?" Diarmuid repeated, not quite understanding.
"Mm… Rosinante," the boy nodded shyly. "My name."
"Oh… I see. My name is Diarmuid—"
But before he could finish speaking, Diarmuid suddenly froze.
Wait.
Rosinante?
Isn't that Doflamingo's younger brother?
Looks like I really have some strange fate with the Donquixote Family…
At that moment, Diarmuid roughly understood what had happened.
From what he remembered, Rosinante had been adopted by Admiral Sengoku when he was very young.
Later he joined the Marines, eventually becoming a Marine Headquarters colonel.
And in the end…
He would return to the Donquixote Family as an undercover agent.
…only to die later on Minion Island.
Killed by his own brother—Donquixote Doflamingo.
Thinking about it now, it seemed Rosinante had already met Admiral Sengoku and had probably become his adopted son. Otherwise, there was no reason for him to be aboard this warship.
With that thought, Diarmuid couldn't help sighing inwardly.
Rosinante was basically a walking disaster.
The kid had always possessed a saint-like personality. In the end, he managed to drag almost everyone around him into trouble.
Doflamingo lost the Op-Op Fruit because of him.
Even the critical mission that Admiral Sengoku had accepted from the World Government ended up failing because of him.
The only one who truly benefited from it all was Trafalgar Law.
In short, if you ever teamed up with someone like Rosinante, you'd better be careful.
One day his compassion might suddenly flare up—and before you knew it, he'd dig a hole and send you falling straight into it with no way out.
Thinking of that, Diarmuid looked down at the half-eaten apple in his hand and sighed again.
So your saintly kindness has already started acting up, huh?
Otherwise why bring me an apple out of nowhere?
"Kid… sigh."
Diarmuid reached out and rubbed Rosinante's head helplessly.
Did I just get dragged into this somehow?
Still, it wasn't entirely bad.
After all, Rosinante now had the identity of Admiral Sengoku's adopted son—essentially a second-generation Marine official.
And judging from Sengoku's later behavior, it was obvious that he valued Rosinante deeply.
After all, Sengoku had remained single his entire life.
He had no biological children.
Most likely, he had poured all those paternal feelings into Rosinante.
Considering all that, Rosinante was still someone worth maintaining a relationship with—for now.
As Diarmuid rubbed his head, Rosinante lowered it shyly, looking embarrassed, but he didn't pull away.
Just then, the half-open door was pushed wider.
Admiral Sengoku stepped inside.
He glanced at the scene in the room.
Diarmuid was leaning against the bed, holding a half-eaten apple while casually rubbing Rosinante's head.
Surprisingly, it looked rather warm and harmonious.
For a moment, something soft seemed to stir within Sengoku's heart.
His impression of Diarmuid improved again.
"Rosinante, I was wondering where you ran off to. So you're here?" Sengoku said with a gentle smile.
Rosinante immediately lowered his head in embarrassment.
Meanwhile, Diarmuid instinctively tried to get out of bed.
But Sengoku stepped forward quickly and pressed him back down.
"No need for that. No need to be so formal."
Originally, Sengoku had only come looking for Rosinante.
He hadn't planned to talk much with Diarmuid.
After all, Diarmuid wasn't particularly special, and there wasn't much to discuss between them.
But perhaps the scene he had just witnessed had touched him somehow.
Or perhaps it was something else.
For whatever reason, Sengoku suddenly felt a bit more goodwill toward Diarmuid.
Sometimes people were simply like that.
Unpredictable.
So instead of immediately leaving with Rosinante, Sengoku sat down beside the bed.
Resting a hand on Rosinante's head, he asked with a smile,
"Diarmuid, how are you feeling?"
"Yes, much better. The doctor said I'll be fully recovered in a couple of days," Diarmuid replied quickly.
"That's good. Don't blame Zephyr for hitting too hard," Sengoku said softly. "It was part of your evaluation. If your body couldn't handle it, staying in the North Blue would actually be better. Compared to the Grand Line, this place is far safer."
"Yes, Admiral. I understand," Diarmuid nodded.
"Good. As long as you understand," Sengoku said with a smile.
"Zephyr seems to think highly of you. He hopes that one day you'll become a pride of the Marines… and his pride as well."
After a brief pause, Sengoku added,
"I'm also quite optimistic about you."
A hint of anticipation appeared in Diarmuid's eyes.
"I won't disappoint either of you."
"Good," Sengoku nodded, standing up. "Get some rest. We still have some business to handle in the North Blue before returning to Marineford."
Then he looked down at Rosinante.
"Rosinante, Diarmuid still needs rest and recovery. Let's go."
Rosinante obediently nodded and reached out to take Sengoku's hand.
The two of them truly looked like father and son.
Honestly, Sengoku was quite something.
Even Whitebeard hadn't gone that far.
Newgate had merely adopted the son of the Pirate King.
But Sengoku?
He had gone straight to becoming the father of a Celestial Dragon.
Impressive.
Just as Sengoku reached the doorway, he suddenly turned back to look at Diarmuid.
"Colonel Diarmuid. You and Rosinante are closer in age. Whether it's on this ship or later at Headquarters, he'll be quite lonely."
"So I hope you'll take care of him."
Diarmuid honestly wasn't too eager to get deeply involved with Rosinante.
Still, he immediately replied,
"Yes, Admiral."