Taitoku Taitoku no Mi

Mastery Mastery Fruit
This paramecia type devils fruit grants the user the ability to spontaneously gain mastery of an action or skill. To change this ability means to swap what you have gained mastery over, for instance if you want to be a master fisherman and use the fruit to gain that then you later decide to become a master chess player you will lose all the fishing skill the fruit gave you.

Weaknesses
If the user uses a skill that exceeds the users muscles they will strain or tear causing injury. Other than that the user suffers the standard devils fruit weaknesses