4 rusted weapons of same type + 1 bahamut horn = that bahamut weapon of that.
4 rusted harp + 1 bahamut horn = bahamut harp.
for bahamut weapon you want to see your class race, harp increase "Harvin" hp by 30%
iirc there are very few harvin in top unit and mostly human so dagger+sword is what people go for.
anyone know the translation for this event fire katana skills?
ah ok, i have 3 sword so i guess i'll try that. is the horn dropped from proto bahamut as well?