A Mercenary Hero is a special type of hero that players can create after purchasing a Mercenary Hero Slot at the NCsoft store. They behave exactly like any other hero, but are copies of your own characters.
Creating a mercenary
- Purchase one or more mercenary hero slots at the NCSoft store (maximum 8).
- Speak to any Mercenary Registrar while controlling a level 20 character.
- Register your current level 20 character (roleplaying character or PvP-only character), which will make it available as a mercenary to your other characters.
- You only need to register a character as a mercenary once; it will then be available to every character except the one that registered it. (i.e. a character cannot use their own clone).
- The appearance copied will be the one the original character has in "Combat Areas", not the one in "Towns and Outposts". To make sure they are copied, set them to "Always Show" or "Hide in Towns and Outposts".
- Some visual effects, like the fire in the Lunatic Court Helm, will not appear in the Mercenary Hero Registration panel and other GUI elements, but will properly appear equipped by the mercenary hero's model. The Divine Halo does not show up properly for Mercenary Heroes.
Unlocking and registering mercenaries
Each character can unlock any available Mercenary heroes by speaking to the Mercenary Registrar, located in the major ports:
- Great Temple of Balthazar (Sebastian)
- Lion's Arch (Valkenhien)
- Kaineng Center (Hayate)
- Kamadan (Alfred)
- Eye of the North (Norman)
To include mercenaries in your party after unlocking, you must define their profession and name by registering one of your characters as a mercenary for the rest of your account. (Until then, the empty slots will be named Mercenary 1..8.)
Newly acquired mercenaries
After registration, the mercenary will be exactly like any other hero, with the following exceptions:
- Mercenaries will use the same armor art, costumes, and festival hats that your character was wearing during registration.
- Hiding a costume, costume headgear or armor headgear with the "Always hide" button will have no effect. You have to remove them completely so they don't get used in the process.
- The armor will be labeled as [profession]'s Mercenary Armor.
- Absent armor components will be treated as invisible armor.
- Mercenaries do not start out equipped with default skills or weapons.
- Mercenaries cannot be added to the party by a character who has the same name as them, but it is possible to add a hero created by a character after that character is renamed. 
All level 20 heroes, including mercenaries:
- Start with no insignias or runes attached to their armor. Players will have to upgrade their armors themselves.
- Have access to all the unlocked skills on your account; heroes (including mercenaries) cannot use PvE-only skills.
- Start out with 200 attribute points.
Deleting a mercenary
- Deleting a mercenary from a slot
- Deleting a mercenary from a slot will remove it entirely from your account; it will no longer be available to any character. You will lose any items (including weapons, runes, and insignias) that any of the associated mercenaries are using across all of your characters.
- To reduce the risk of accidentally losing items, you will be forced to manually type in the mercenary's name.
- You can re-register the same character once it has been deleted.
- You must delete a mercenary in order to change its appearance or name.
- Deleting a character that was the parent of the mercenary
Deleting a character from which a mercenary has been made will not remove the mercenary from your account.
Modifying a mercenary
Mercenaries cannot be edited, the only way to change the appearance of a mercenary is to delete them and create another with the same name in the same slot. However, to avoid losing any equipment, do one of the following:
- Remove any armor, weapons, runes, or insignias or
- Immediately create the new mercenary (with the same profession) before logging out or zoning.
You will lose the profession-specific armor upgrades if the new mercenary has a different primary profession; you will lose the weapons and common armor upgrades if you change districts, characters, or outposts.
- The only differences between mercenary and standard heroes are that players have full control over their names and appearances.
- They can use customized items for the current character, not items customized for their parent characters.
- Tonic forms are not part of armor; they will not be copied during mercenary registration.
- A quick way of creating mercenaries of any profession would be to create a PvP-only character (already at level 20), give them appropriate armor, costumes and/or hats, and register them. Delete that PvP-only character and create a new one in the profession of choice using the same character slot. With enough mercenary slots, you can create several heroes with the same profession and similar names using this method, without the need of making extra permanent roleplaying or PvP-only characters.
- Whenever the game has no access to a mercenary hero's appearance (e.g.: when they are outside compass range) they will have the appearance of a Doppelganger in the user interface panels.
- Before using the Doppelganger model, they used the stick man model.
- Introduced in the March 3, 2011 update.