Really interesting to note that the royals (sans Alear and Veyle) don't have prf weapons which is surprising (also rip Alfred, Céline and Fogado who wont be able to use the S rank weapons in their special classes oof).
Speaking of S rank weapons, seems like Nova is our S rank tome I think. Also swords, lances, axes and knives have two legendary weapons, a basic one and one that acts as a smash weapon. The S rank staff fully charges someone's engage meter.