There is no supreme overlord of Mars. Mars is a planet, and as such, it is not ruled by any single entity. There are no known sentient beings or governments on Mars.

It's possible you're thinking of science fiction, where the concept of Martian rulers is common. In fictional stories, there have been many interpretations of Martian leadership, ranging from advanced alien civilizations to rogue humans establishing colonies.

However, in reality, Mars is currently uninhabited and is only explored by robotic probes and rovers sent by various space agencies.