After BlackDale, anyone know why David know about Wagram name, despite his name never mentioned before, in the cutscene they only discover that the white mage are affiliated with the Academy, and nothing else, or did i miss something in the process, i already re-watch the cutscenes and found nothing about Wagram name before David mentioned it after BlackDale event

Question is in the comment...

I've been playing this game over and over again since it first came out on XBox (1998). Now I am enjoying this game on the PS4 (the old PC version) and on new game plus. I made sure that I bought the Ragna Rock when it first came available and upgraded my weapon to Enchanted Bluesteel at beginning of game. I just got to level 79 (haven't rescued Irina yet) and there it was.....Rush learned Cerulean Rain!!! When I first played the game (not on new game plus), for the life of me I could not get him to learn any special weapon arts. I swear, that Ragna Rock on new game plus ("bonus unknown") is leveling up EVERYTHING and EVERYONE quickly.