Aion Riftshade

Can someone tell me where I can get this recipe <Design: Expert Durable Adamantium Sword> ??

I finally done the craft lvl, but the sellers don’t have such a recipe.

I saw it at an auction, they sold it somehow a couple of times.

I looked through all the bases, but nowhere did I find information from which mobs it can be drop.

Asmo side!

I"m almost sure that it drops in brush to in but to know from which mobs u should search in aioncodex