Dr. Gaia

"Beautiful! I finally have the power of the gods. With this machine, I can be a god myself. The world belongs to me!"

- Dr. Gaia when his energy machine reaches maximum levels

Dr. Gaia was one of Black Ghost's top scientists and an old colleague / rival of Dr. Gilmore. He is the creator of the Mythos Cyborgs and the primary antagonist of the "Mythos" arc.

History
Dr. Gaia was a colleague of Dr. Gilmore back when the latter was still a member of Black Ghost. The two argued quite often due to their conflicting ideals. Gaia had wiped his cyborg's memories, believing human emotions to be a weakness. Gilmore disagreed, believing emotions to be a strength.

Later, after the apparent fall of Black Ghost, Gaia laid low for a while but eventually resurfaced along with his Mythos Cyborgs. Upon awakening them, Gaia told his cyborgs that they were Greek Gods come to punish humanity for its sins.

When Apollo let the 00 Cyborgs after defeating them, Gaia questioned Apollo as to why he didn't kill them. Apollo simply stated that he would vanquish them eventually.

When Artemis lost the will to continue their mission, Gaia confronted her at a cliff and shot her to prevent her from interfering with his plans. Around that time, the 00 cyborgs learned of Gaia's involvement with the Greek Gods and Dr. Gilmore, 001, 007 and 008 set out to stop him.

The four confronted Gaia in his control room, where Gaia's reactor had reached maximum levels of energy. Gilmore warned Gaia that the reactor would overload, but Gaia didn't listen, stating that he could use it to become a god. Just then, Apollo arrived in the control room, having learned that Gaia killed his sister. Apollo killed Gaia by shooting him through the chest. The scientist's body eventually disappeared after it fell it Magma Island when it collapsed.

Trivia

 * Dr. Gaia's name is derived from the Greek mythological figure Gaia, the progenitor of the Greek Gods.