After returning to Impel Down, Carlos hid inside the Kamui Space. Instead of eating, drinking, and having fun, he quietly digested the insights he had gained from fighting Shanks and watching Kaido and King's battle.
Although these insights could not directly improve his strength, they could indirectly enhance his combat skills and his command over power.
The One Piece world was no other world. Insights were important, but the most important thing was still improving one's own strength.
Improving one's own strength was true improvement, and the foundation of strength was stamina. Whether one followed the path of swordsmanship, Body Techniques, Haki, Devil Fruits, another path, or a balanced path, all of it consumed stamina.
Thus, Carlos never stopped training every day. He needed to constantly improve his stamina, increase his Pupil Power, temper his spirit, and forge his body.
In the Warden's office of Impel Down, Sengoku, then a Marine Admiral, summoned Magellan and Shiryu into the office separately to talk. On the surface, he never mentioned the matter of Impel Down's top position. Instead, he chatted with them about everything under the sun, from official business to private matters, from political affairs to local customs...
After more than two hours, Sengoku had gained a fairly detailed understanding of both men through their words and behavior. Deep down, he favored Magellan, whose values were closer to his own. He liked Shiryu less than Magellan, but he did not dislike Shiryu either.
When King had been in office, interrogating and abusing prisoners had been common. With a Boss like that, those below naturally followed suit. Interrogating prisoners for intelligence was normal. Everyone in Impel Down had interrogated prisoners, though not everyone had abused them. Still, there were quite a few who had.
After all, even Impel Down's highest-ranking Boss