Information of Sky Island Debuff

Hi guys any one can help me saiding me why my characters are weaker in Sky Island??
who are the target of the Debuff??

Thanks very much in advance

All characters not native to Skypiea are affected and the effect gradually loosens as you advance in stage.

Damn it That is a crazy Debuff
So i must do all Sky Island without Captain ability e with a debuff in stats??!! they are very crazy !!!

Thanks Very Much for the reply

Captain abilities work fine... only the character attributes are affected