Shikai to Bankai?

cloudbatz

as the title says how do you make your zanpaktou to shikai lvl to bankai is it from reiatsu or .....? and is it worth it to make wabisuke to shikai up to bankai lvl or just wait till i get Haineko? am at lvl 43 atm

PAOFUI

u upgrade them at the zank option... n u need a certain reiatsu to get them to bankai n then hog yukai...