The Birch Guard

Completely anonymous, and dressed in dark green cloaks, the Birch Guard has sworn to protect the Alchemist during his pursuits.

Uniform

The Birch Guard gets their name from the white wooden mask that they always wear. These masks cover the full face, even the mouth, and the backs of their heads are concealed by a dark green hoods. While the guards are humanoid, there's no way to tell what race they specifically are, as all features are completely obscured. Even the two holes cut for the eyes are hidden by a shaded glass that removes all expression from the guard.
All of them wear cloaks that fall slightly above the knees. The cloak closes in the front around the neck. It's dark green in color. Beneath the cloak, the Birch Guard wears all black. Their clothing is somewhat loose fitting, allowing for plenty of maneuverability. 
Some members of the Birch Guard carry quarterstaffs, while others carry thin swords. The swords are usually concealed beneath the cloak. It is very rare to see a Birch Guard member with their sword drawn.

Anonymity

Everything about the Birch Guards' lives is hidden, down to where they call home. A couple of them can be seen following the Alchemist wherever he decides to show up, but none know where they go afterwards. Occasionally, a member of the Birch Guard will be seen by themselves, likely tracking down someone that the Alchemist wishes to talk to. There is actually no way to tell how many members there are, as all of them dress identically.
It is unclear how people apply and join the Birch Guard, but the assumption is that new members are personally invited by existing members. In order to receive an invitation, the fighter must demonstrate their combative capabilities to a guard member, as well as build a certain baseline of trust.

The Great Oak Oath

The Birch Guard lives by a very strict code of conduct called "The Great Oak Oath." This oath that they swear by is what got them working for the alchemist. The guards were so honor bound, that they promised their lives in exchange for gifts from the Alchemist.
Promises included in this oath include: Never leave a member behind, never take off your mask in public, abstain from gambling, never go back on your word, always give more than you receive.