Farming up Fatui Agents would be needed as many weapons need this material to upgrade them. Fortunately, these agents are found around Liyue and often found alone for easy pickings. Here's where you can find these agents and get those sacrificial knives off them.
Where To Find & Farm Fatui Agent Knives
Currently, most of the spawn spots of these Fatui Agents are mostly in Liyue. Finding them is easy as the Adventurer's Handbook allows players to track them in-game. Simply browse the handbook and scroll down until you see the face of the Fatui Agent. Press the Navigate button and the game will immediately track them on your map for you to find and beat them.
Fighting Fatui Agents
Once finding them in their spot, most Fatui Agents operate alone which makes them an easy target to fight. However, players should still be careful as their attacks still hurt characters that have good equipment.
Carefully dodge their attacks and strike back swiftly before they cloak themselves in plain sight. If they do manage to cloak up, players can see a faint image of the Agent running around in the area. The game's automatic attack tracking system will not work on them and players will have to manually aim their swings and arrows to hit them.
Players can also hit them elemental reactions to render their cloak useless as the elemental debuffs will immediately give their positions away. Fortunately, the Fatui Agents doesn't have high defense and will fall quickly if hit with many strong attacks.
Why You Should Farm Fatui Agent Knives
Once defeated, these Fatui Agents will drop sacrificial knives and Fatui Insignia of varying rarity. These sacrificial knives are important as they're needed for some weapons considered strong in the game. Weapons that need these sacrificial knives include:
- Blackcliff Agate
- Blackcliff Longsword
- Blackcliff Longbow
- Crescent Pike
- Lion's Roar
- Lithic Blade
- Solar Pearl
- White Tassel
- Primordial Jade Winged-Spear
- Summit Shaper
If you ever get these items or new weapons introduced in the future, upgrading their refinement would be easier in the long run.