The Black-Clad Servant

The Black-Clad Servant (real name unknown) is a muscular male who serves Susan Wise toward the end of Azumanga Randomness. He is first seen knocking out Hannah Benfield and the First Doctor so that his mistress may take Nyamo's body.

The Servant originally carries a massive weapon and wears body armor, although both are disposed after Susan possesses his body. This is due to her mind powers, although she alters his body structure to make it more feminine.

It is possible, although not the author's original intent, that the Servant is a brainwashed Shayde.

Canon

 * Azumanga Randomness