Deserter

Walkthrough
Break the weapons of at least one enemy. Disarm all 22 enemies for full points. Points are deducted for each enemy killed rather than forced to surrender.
 * The agents are the Lamiae and Merrows that are roaming around.
 * The NPC at the start tells you that you need to subdue them, but don't kill them.
 * "Your mission is to swiftly disarm the deviants and take them into custody."
 * To succeed, you must break their weapons.
 * The only thing that makes a mob's weapon break is critical hits.
 * A Monk using Backhand Blow or SATA from a Thief or /THF will be useful.
 * Any weapon skill that has "Critical damage" or "Chance of critical hits vary with TP" will help too.
 * Once the weapon is broken you get a message, "The target has thrown down its weapon," and it becomes an NPC. Further clicking on it says "The target has surrendered."
 * You only need to disarm one to win the Assault.
 * In order to unlock the Rune of Release, talk to the NPC at the start. He will ask you if you want to abort. Choosing "Yes" unlocks the Rune of Release.