Which characters are confirmed to have regressed in BP? Which are suspected to have regressed? How long does regression continue for?

[Warmmedown]

Known: Gohan between Cell and Great Saiyaman

Suspected by me: Chi Chi between 23rd BT and Vegeta. That's 6 years. Maybe beyond that too.


If Buu Saga never happened and Gohan carried on not training for another 7 years, would he have become further weakened? There's some bottom level that would be reached.

Freeza seems to be able to not do much, but still retain his power. He could predict his own power level, and wasn't surprised by it, indicating it never dropped. So his race may require less maintenance. A saiyan, namekian and human may all have different BP regression curves.

 

[Spiral-Force]

Sick Goku was a shell of his standard Super Saiyan self, PL-wise. Just being in the form was said to make the condition worse. But he scaled back to normal after the bedridden / antidote period.

 

[SSJ2]

Piccolo implies that Kami lost power:

Chapter: 182, P9.5
Piccolo: “Truly Son Goku is nothing but an obstacle for me…Far more so than God, who neglected his training.”

Roshi/Tsuru lost power after their prime years.