This one piece Au's is called Devil fruit corruption, all Devil fruits users are separated from each other and their crew all the people who isn't effective by it is looking for a cure for them

The paramecia Devil users only have 3 stages but for Logia has 5 stages.

Your jobs to help them and mark down their results.

(The people who are infected are only devil fruit users like luffy, chopper, Robin, kidd, crocodile, buggy, etc)