All of them:
- Shanks hasn't done anything the entire 1000+ chapters.
- Black Beard hasn't done anything the entire post time skip.
- Dragon hasn't done anything the entire 1000+ chapters.
- Mihawk hasn't done anything the entire 1000+ chapters other than train the person that wants to defeat him and it was off-screened.
- Imu is a filler character, not even worth mentioning in the same light as the other characters.