Ubiquitor

An immeasurably ancient being trillions of years old (older than the universe itself is reputed to be), the Ubiquitor is one of the Absolutes, supremely powerful beings. The Ubiquitor's power is such that she can exist across the multiverse in multiple locations simultaneously, and bring about the creation or final destruction of a galaxy. That is her purpose- a harbinger of doom, who detects the impending end of a galaxy and brings that end about. She also employed the mercenaries Silverback, Ganglia, Hazmat, and Savant- all survivors of previously destroyed galaxies- to battle any who would attempt to stop her from meeting her goals.

In the 31st century in the Guardians of the Galaxy's timeline, the Ubiquitor came to destroy the Milky Way Galaxy, and was narrowly defeated by Phoenix IX (whom she was attracted to) and Woden, the son of Thor. She was apparently destroyed- but when dealing with a being such as the Ubiquitor, it is likely that somewhere, somehow, she still lives.