Becoming a member of the Master's Guild means you are officially recognized as a Master on the RPG. There are several benefits to this as well as a few drawbacks.
Being a Master will increase your fundamental technique slots by +10, your advanced technique slots by +5, your power up technique slots by +3, rush technique slots by +1, and your custom technique slots by +5. You may create one custom finisher. All techniques do an additional +1 damage rating level. You can also designate one of your advanced or custom techniques as your "Signature Technique." Doing this will
further increase the damage rating by another +1. This damage rating increase is also passed onto any of your students who learn your signature move from you.
As a Master you can teach any move you know to someone else while partner training with them. They will pay the highest amount of SP among NPC masters to learn it (if it's a custom, they will pay what you paid to learn it). Teaching someone else a custom will count against
the slots for that particular category of technique, not their
custom slots, meaning you can propagate your customs far and wide as if they were an official technique of the site. Whoever you are training will also gain +1 fighting style level after every four consecutive weeks of training with you, but only if their fighting style
matches one of your styles. You also gain +1 fighting style level for every four consecutive weeks of training with them.
Being a Master is not for everyone. There are a few drawbacks to dedicating yourself to teaching others. First of all, you can never change your job out of Job Set 2. You can stop doing a job if you so please, but if you ever do a job, it must be within Job Set 2.
Secondly, all of your techniques are limited to use once per battle. Even techniques that normally have no limitations, like heal, are now limited to use once per battle. Your Signature Technique, however, can be used twice and there is no limit on fundamentals. Nothing can increase the number of times you may use them. Exceptions include bukujutsu, power fly, and speed teleport. Being a master also allows you to Master 3 more Fundamental Techniques and 1 more Advanced Technique.
Masters may use weapons, but they may not use, nor teach, weapon techs.
Finally, a Master cannot be a member of any other organization
Once you become a Master, you can never "unbecome" one. Think about it before committing yourself!