Armonia Final Episode Patch Notes (v23.97.53) says:
The “Strata Devil Weapon Recipe” can be obtained from “Naraka’s Alchemy Table” with a certain chance.
Alchemy Table of Naraka can be accessed from the Alchemist Jenia in Viron (F7). Unlike the standard alchemy, this does not consume any Vis. I attempted this 200 times using 200 Pieces of Naraka - Lu, Beel, Al, Mo, Ma, Than, and He. The result is:
|Piece of Naraka||122||61%|
|Symbol of Naraka||78||39%|
|Recipe - Strata Devil Weapon||0||0%|
|Recipe - Broom of Little Witch||0||0%|
Most of the time, you will get 1 Piece of Naraka for using 7 Pieces of Naraka. LOL! We can conclude that the average rate for weapon recipe is less than 0.5%. The difficulty in enhancing weapon in Armonia Final Episode is supposed to be offset by the ease of getting weapon recipes and materials... Yet this is the typical bull shit we get from IMC game design.