The Forerunners from Halo. The Forerunners possess extremely advanced technology, including the ability to manipulate space-time, create artificial worlds (Halos), and near-immortality through technology. Hard light technology, slipspace (FTL travel), advanced AI, and highly advanced architectural engineering.
The Protheans from Mass Effect series. Ancient beings with the ability to control and manipulate entire galaxies, creating the Reapers. The Reapers are ancient, synthetic-organic starships with vast technological prowess, including indoctrination and massive-scale space travel. There are also the Leviathans, an ancient race with advanced technology capable of mind control and influencing the development of other species. Indoctrination technology, near-indestructible synthetic-organic starships, galaxy-spanning control mechanisms, massive firepower, mind control, advanced biotechnology, and creation of synthetic life.
The Combine from Half-Life. Interdimensional empire with advanced military technology and the ability to conquer and control entire worlds. Dimensional travel, advanced weaponry, and bio-mechanical augmentation.
The Zilart from Final Fantasy XI. Ancient race with advanced magic and technology, responsible for the construction of massive structures and powerful artifacts. Magical technology, advanced engineering, and control over powerful energies.
The Endless, the Sophons, the Cravers, and the Vodyani from Endless Space. The Endless were an ancient and highly advanced civilization known for their significant advancements in science and technology. They were able to achieve virtualization, allowing them to upload their minds into machines, effectively granting them eternal life. Advanced nanotechnology, control over Dust (a powerful substance used for various technologies), and significant influence over the galaxy’s civilizations through their artifacts and technology. The Sophons are a highly scientific race dedicated to research and innovation. Their pursuit of knowledge drives their technological advancements. Rapid scientific research, advanced starships, and sophisticated energy weapons. The Cravers are a bioengineered race created by the Endless, known for their relentless consumption and assimilation of resources. Efficient but destructive resource harvesting, advanced war technology, and bio-mechanical integration. The Vodyani are a theocratic civilization that relies on advanced technology to harvest life-force (essence) from other beings. Advanced life-support technology, essence extraction, and powerful ark ships.
The Chozo from Metroid. Ancient race known for their highly advanced biotechnology and architecture. Power suits, advanced weapons, and the ability to manipulate biological organisms.
The Dwemer from The Elder Scrolls. Ancient race with advanced steam and tonal technology. Mechanical constructs, advanced metallurgy, automatons, and powerful artifacts.