How to Recruit Mercury - Dragon Quest 6
Mercury is one of the available optional characters for players to recruit in Dragon Quest 6. In order to recruit Mercury to your team you'll first need to complete the game and make a post game save file. Once you've done this load it up and Zoom over to the Suite Dreams which is located in the Dream World. If you don't have this Zoom location then fly over to the Suite Dreams which is just north of Castle Graceskull.
In the back of Suite Dreams you'll find a door (pictured below) which will lead you to a forested area that resembled where we found Peggy Sue earlier in the game. Chase Mercury around a few times and the man here will talk to you and offer to help you catch the slime in the same way we caught Peggy Sue.
Note: He is not available in the SNES (original release) of the game; only in the DS and Mobile remakes are you able to recruit him to your party.
Vocation Permanent Rewards
These are the passive & permanent rewards that you will get when mastering a Vocation. You'll keep these boosts even when switching to a different Vocation. Once you reach level 5 in every Vocation you'll receive a Gospel Ring from the priest in Alltrades Abbey as well which will allow you to avoid encounters. You do not need to reach level 5 in every Vocation on 1 character, it can be done on multiple characters.
Gladiator: +20 Strength
Armamentalist: +20 MP
Paladin: +20 HP
Sage: +20 MP
Ranger: +20 Agility
Luminary: +15 Style (or 20)
Hero: +40 MP
Dragon: +20 Strength
Liquid Metal Slime: +100 HP