please stop making the mc take action and quickly solving the problem. you did that when visiting Doflamingo and killing Orochi. the whole point should be people reacting to the manga and how it changes their faith let me give you an example - you can write that the mc just fly's to Brook and bring him back. Or you can write how many people went to find brook in the fog because of his unique condition. the marine would want him . the celestial dragons would want him and descendents of the dead crew mates . how it becomes a hide and seek game in the fog. lastly brook finds out that he has become famous from some hunter team. in conclusion, I know you like to keep it simple( with how the mc can just throw immortality to anyone.) but you need to know that the mc interfering and cutting plot threads is less satisfying then things just working among the characters