The weapon mastery achievement in "Dynasty Warriors: Origin" is a special achievement in the game. To achieve this achievement, you only need to use 9 kinds of weapons to win in the battle, and use a total of 9 kinds in the battle. Once for each weapon that can be obtained during the process.
How to obtain the weapon mastery achievement in Dynasty Warriors Origin
Weapon Mastery
Used 9 weapons to win the battle
Use each of the 9 weapons obtained in the process once in total during the battle. Even the small tasks on the map meet the conditions, and it seems that they can be replaced in battle, and the calculation is based on the weapon used in the final victory settlement.