As of now, Straw Hat Pirates are one of the strongest pirate crews in the whole series, with very reliable members who excel in battle, navigation, stealth, medical knowledge, archeology, and engineering…
They already proved themselves to be a real threat to the World Government and pirates as well, but as foes get stronger with each arc, Straw Hat members are ought to improve as well in what they do, especially in battle and fights.
Right now Luffy has finally awakened his devil fruit and has mastered all three types of Haki and its advanced applications. At this point it really looks like Luffy has reached Yonko level.
But what about the other 9 Straw Hat members? I think it will goes like this:
Zoro
Masters Advanced Conqueror’s and Armament
Creates a Black Blade (like Ryuma and Mihawk)
Improves Observation
Sanji
Unlocks Future Sight (Advanced Observation Haki)
Unlocks Conqueror’s Haki
Improves Armament Haki
Usopp
Kabuto has seastone coated on it (Increase range and power of shots)
Usopp will become proficient in Observation Haki
New variations in ammo
Franky
Shogun Franky becomes more streamlined, think Isaac from World Seeker
Franky upgrades his suit to incorporate Seastone into his fists
Unlocks Armament Haki
Nami
Zeus Climatact infused with Seastone
Flight (By riding on Zeus)
Unlocks Observation Haki
Is able to create a thunderstorm over a country (Ultimate Move)
Nico Robin
Flight through Wings
Unlocks Armament Haki
Unlocks Awakening of her devil fruit thus making her able to create physical copies of everything she touches.
Chopper
Accessing the Monster Point without a rumble ball
Improves endurance
Unlocks Armament Haki
Brook
New Sword (A Meito- Personally I think he should get one of the 21 O Wazamono Swords)
Greater Ice Generation
Full Body Armament Haki (like Pica and Vergo)
Unlocks Awakening of his devil fruit, allowing him to manipulate souls of everything he touches.
Jinbe
Unlocks Advanced Armament Haki
Gains some dope ocean related powers.
*Theory by stealth_hawk
