Frau Boom-boom was the first of the robots built for the Charwoman. The fact that she is a maid is Wily's attempt to spite Charwoman. Boom-boom has powers which give her control over the dust of the earth. Despite her harmless appearance, she can use her attacks with deadly efficiency.

Frau Blüher (horses neigh) and Centaurman, while actually two robots, fight as a pair. They work together well, and make a dynamic, deadly duo. Frau Blüher (horses neigh) was built by Charwoman herself, while Centaurman was adopted by her after his battle with Mega Man.

While Siberia is a polar researcher, she is completely loyal to Charwoman. She controls the element of water, specifically in the form of ice. She is respected by her sister robot masters because of her grace and speed.

Amazonia is one of the most flamboyant of the female robot masters. She likes to show off her powers in battle. These powers are formidable, as she commands the plants to do her bidding. She also has very effective attacks of her own, including a deadly whip.

Hera, named for the goddess of Greek legend, is a good match to her namesake. She is evil to boot, and cruel in only the way a scorned woman can be. Strangely, she has yet to even be scorned. She controls the power of light, able to solidify it into the weapon of her choice.

Hecate holds control of the forces of magic itself. She has an Aether Engine of an advanced type that the world has never seen before. Her capacity for magic is equaled only by Bill and Roll's systems, and even then, the powers she commands are some of the most advanced in the world.

Diana is a junior scientist under Charwoman, her job being similar to Frau Blüher's. She is a master archer and skilled in the use and shaping of all kinds of metals. She is very fast and can climb walls and ceilings as a result of the semi-liquid metal coating her body, which also acts as an effective shield.

The exact opposite of Hera, Lillith is alluring and seductive. She holds sway over the powers of darkness, and is able to crush her opponents with the minimum of effort. Lillith is able to shape-shift, alternating between a flying form and a more heavily armored ground form.

Andariel's name comes from one of the rulers of hell, and she shows it with her mastery over the force of fire. She throws Fireballs with relative ease and can splash around acid to burn away her opponents defenses. She is the most beautiful of the female robot masters, and one of the most deadly.

While it's true that these are not really robot masters, they are a constant adversary to Roll and Chris. And also let's face it, these things should not exist. They were spontaneously created by Dr. Wily's toilet after a few moths of no cleaning. They have no real weaponry, unless you count the fact that they can reproduce like there's no tomorrow. They are so cute that only Roll and Chris can bring themselves to kill them, so maybe that's a weapon as well.

The Maseiryoku is one of the most powerful of all demons. Drawing its powers from the force of entropy, it is one of the most dangerous and destructive of forces. The one inhabiting Dr. Light first took over around the events of Mega Man 8. Since then it has been slowly taking control of Dr. Light, resulting in many of the personality changes that have occured (Dr. Light used to not be a pervert, nor lazy. He always did drink, however, that's Mega Man and Wily's fault). Ma-Light is the name given to the creature when it has complete control of the good doctor, something that has been happening with more regularity of late.