User blog comment:Jopjopjop/Volume 20 Spoilers/@comment-110.22.99.149-20150727165422

Just an idea & i don't know if anybody else has thought about this yet to do with the "King Piece", Kuroka mentioned that her previous master was a power hungry person who would experiment on his servents & their family members & make them go through crazy power-ups, & as we know she then killed him to protect Koneko, i now wonder if this is what he was using back then, or at least gave Ishibumi the idea for this later part of the story.

Anybody elses ideas on this would be more than welcome as well ;)