What line i'm not seeing that in the chapter anywhere ??? maybe i am just missing it ? Also i think you are sort of downplaying him a bit. Firstly the narrator box (oda) confirms he would be world known as the great shogun of wano he has already skipped forward in years...he has kaidos mythical fruit which can do everything kaido fruit can maybe he awakens it by being one with the fruit unlike kaido if that is a thing. The swordsmen of wano know ryou, yamato can teach him how to flow ( if he is a conqeror). The chapter already hypes his oden like body as being sturdy. It can easily happen imo, the chapter hypes him as one day being the great shogun of wano and the greatest samurai in the nation lol just seems weird to say it won't happen when oda hyped this up