Guild Wars 2

just wondering if anyone knows which npc sells the recipie to create destroyer weapons, and also which mobs drop destroyer lodgestones. thank you in advance

As far as I am aware you cannot purchase a recipie for these, you have to discover them. One known recipie is:

30 destroyer loadstones + Ancient Staff Shaft + Ancient Staff Head + any 1 of the exotic level 80 inscriptions.

Alternatively, if you like the flame appearance you could always run Citadel of Flames which has really excellent and similar skins to those of the original Guild Wars 1 Destroyer weapons.