Dr. Halsey

Dr. Halsey is an insane scientist and one of the leaders of the Empire of Chaturn.

Description
Dr. Halsey is the head scientist of Chaturn and one of its leaders, seen issuing orders to characters like Doom Guy. She created the traitorous Spartan 117 and famously failed to recruit the Sun, instead being told to "fuck off" and crashing into Mercury. She also approved the construction of the Death Star which exploded due to problems with its gravity well, killing everyone on Mercury.

Due to her frequent incompetence and lack of sanity, she is not considered a special resource of Chaturn.

AI Invasion
Dr. Halsey led Chaturn's scientists in the project to create a clone of Master Chief called Spartan 117, which immediately betrayed the Empire and joined their enemy, the Humans of Earth.

She went alone in her spacecraft to attempt to recruit the Sun, but the Sun told her to fuck off. Shocked by this, she immediately made a wrong turn and crashed into the surface of Mercury, but survived and escaped.

When the Empire recruited Doom Guy, Dr. Halsey issued the order for him to kill the Sun. She also approved the creation of a Death Star which immediately exploded and destroyed all life on Mercury.

As the lead scientist of Chaturn, Dr. Halsey presumably led the project to create Sun Tzu, which is small, ugly, and mean, in defiance of Empress Ghost's wishes for it to be big, beautiful, and nice.

After the Dougtopian Empire created Sun 3 by harvesting energy from Sun Tzu, Dr. Halsey flew over to Sun 3 and told it to "fuck off," still angry about the time the first Sun told her to fuck off. This caused the Dougtopian Empire to lose control of Sun 3, which was a win for Chaturn, their enemy.

When Chaturn acquired the planet of Uranus and renamed it to Ouranus, Chaturn's top scientists began construction of a Mega Toilet. In the process, they also invented nanobots, which some of the scientists injected into themselves, becoming super-intelligent machines called the Chatronomicon. It is unknown if Dr. Halsey was among the scientists who became the Chatronomicon, but it is not unlikely considering her insane nature. The scientists then created a Mega Robot Suit, which was never really used by Chaturn, but it sounds cool.

The top scientists, including the Chatronomicon, then built a new moon for Ouranus made out of cheese, called Moon Tzu. They also figured out how to create life from cheese, creating little animals made out of cheese called Cheese Creatures. They then finally finished the Mega Toilet on top of Moon Tzu, which was the size of Ouranus.

Alternate Timelines
At least one alternate universe version of Dr. Halsey is known. She is a war criminal.