Is Tsugikuni Yoriichi Zephyr's disciple? Yes, and no.
Yes, in a sense.
After Tsugikuni Yoriichi was brought back to Marine Headquarters by Garp, he was indeed greatly looked after by Zephyr. However, Zephyr had not taught Yoriichi all of his abilities. Yoriichi himself possessed extraordinary talent, and after going to sea with Garp, he quickly found his own path.
Afterward, he spent many years training in peace on Boin Archipelago.
Both Garp and Zephyr had played more of a guiding role in Tsugikuni Yoriichi's growth.
That was precisely why Zephyr had reacted as he did when Garp claimed that Tsugikuni Yoriichi was a disciple he had taught.
He would not belittle himself, nor would he think too highly of himself.
Zephyr had a clear understanding of just how capable he was.
Although Zephyr did not believe Tsugikuni Yoriichi had attained his current strength because of him, he would not turn Ace and Sabo away in front of the two children.
A genius like Tsugikuni Yoriichi hardly needed anyone to teach him, but Zephyr did not think he was incapable of teaching Ace and Sabo.
Though the two children had displayed remarkable talent, turning that talent completely into strength would still require countless grueling training sessions.
Letting the two children grow wild was not necessarily a good thing.
When Ace and Sabo heard that Zephyr had once taught Tsugikuni Yoriichi, both of their expressions changed.
The two, who had originally held no interest whatsoever in Marine Headquarters, were now filled with curiosity and longing toward Zephyr, the Marines' former chief instructor who had taught Tsugikuni Yoriichi.
Children's thoughts were always simple. If Zephyr could teach one Tsugikuni Yoriichi, surely he could teach a second, or even a third!
Garp noticed the subtle changes in Ace and Sabo's expressions. A faint smile