At least other yonkos have a Devil Fruit, what does have Shanks? Haki isn't a fighting style in its own, it only helps to improve the fighting style you're already using
He pull out a gun or he starts fighting using his head like Don Chinjao? Or he fights using black leg style?
He pull out a gun or he starts fighting using his head like Don Chinjao? Or he fights using black leg style?
The only logical conclusion is that Shanks is not JUST a sword user, unlike Mihawk.