Saidai Saidai no mi

Introduction
The Saidai Sadai no Mi or Largest Largest fruit is a devil fruit that permently changes the users body in order for them to be the largest thing in the room. If a giant walks near the person they will become bigger than the giant. If a tall man walked up to him and without the giant being present they will become larger than the tall man.

Weaknesses
The user suffers from standard Devil Fruit weaknesses