Fear Status Effect

Fear has three effects:

1. Trembling animation, or camera shake for 1st person player view.
2. Movement towards source of fear is affected by Slowness.
3. Movement away from source of fear is affected by Swiftness.

Thus, Fear is actually beneficial in some ways (escaping danger) and doesn't take away the player's agency.

Fear would be useful both as a potion and as a mob special ability.