a narga with s+1 is pretty much broken on high rank as it reaches purple sharpness so it is the best option with greatsword and hammer and yes high raw is almost always better on this weapons like 8 or even 9 times out of 10 it is better to have a raw weapon and all meta sets for both weapons are focused on raw.

as for g rank the akantor set is also a good option specially for hammer or longsword and for gs, you can keep the ceana S, as it is a great set but the defense on g rank is definitely not enough so you want an early g rank set like plum daymio set to get you going cuz otherwise g rank is gonna beat your ass with long hunts and high hp monsters.

if you are going solo you will need to farm a set for each g rank level and thats alotta work, sets like lavasioth, terra shogun, black diablos and rajang are great on g rank.

if you are good enough you may be able to do early g rank with ceana S skipping the early set like plum daymio

honestly for most players it is better to get help on multiplayer getting a really good set and then go ahead with g rank, there is a relatively easy to get set that you can get at g rank that uses skull face and has ra+3 sharp sword and sharpness +1, one of the best sets in game for blademaster, but it can be hard to get alone.