How to Recruit Kingsley - Dragon Quest 6
Kingsley is another one of the optional slimes that you can recruit to your party in Dragon Quest 6. In order to recruit Kingsley you'll need to complete up to rank 7 of the Best-Dressed Contest in Château de Sass, a town in the northwestern portion of the Real World nearby Wellshire.
Once you've completed rank 7 all you need to do is speak to Kingsley who is on the first floor of Cheateau de Sass (pictured above). He'll ask to join you, say yes and that's all there is to it. Kingsley is one of the more powerful slime companions that you can get to join you in this game, on par with Goowain.
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.
Kingsley Vocation Advice
Kingsley is the most powerful slime companion that you can recruit to your team and comes with very well rounded stats making just about any vocation good for him. If you haven't completed Slimopolis yet, Kingsley is a great choice for battling in the arena. Goowain is typically used because of how much easier he is to recruit to your team than Kingsley and Goowain has much better gear choices.
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