Nami is the navigator of the Strawhat Pirates. She is one of the best navigators in the world in my opinion as she has used her navigational skills quite a lot of times to save Strawhats from bad weather. We saw Nami take away Zeus from Big Mom. We saw how powerful Zeus is and it’ll be a perfect weapon for Nami. She can use Zeus even more dangerously than Big Mom, at least I hope that’s the case. Strawhats powers Wano Country war seem pretty awesome.
3. Vinsmoke Sanji
Sanji is one of the strongest fighters of the crew. We haven’t seen his full strength after the time skip yet. In my opinion, Sanji will use advanced Observation Haki in Wano war as his powerup. Also, we know that he now also has a Raid Suit which gives the user incredible strength. Even though he said he won’t use it but when there won’t be any option left he might have to use it out of necessity. And Wano war will be full of these sort of situations.