"We do not know who they are or why they would attack us"-Sasha commenting on the Tyran Civilization
In the context of the Legend Universe, the Tyran Civilization is a highly advanced, intergalactic civilization who were the creators, progentors, and at one point masters of both the Precursor Civilization and the Koozer-Ga, but not of the other civilizations, who they did'nt see as worthy of their attention. They attempted to keep The Mantle to themselves, while the Precursors believed that they should allow all sapient creatures to share in it's protection. This was a flashpoint in the Precursors' relationship with their masters, which led to all-out war. After being defeated by the Precursors and forced out of the Galaxy, they swore to return.
"long ago, an advanced civilization, the Precursors, tried to rule the galaxy peacefully, but history had other plans; another civilization, the Tyrans, were based on warfare"-Cynder III explaining the Precursors to Xinxala
almost 400,000 years laters, nearly every trace of the Tyran civilization had been destroyed and the Precursors held complete dominion ove the MilkyWay and nearby startclusters. Eventually reaching a point at which they believed they no longer needed to wage war, the Precursors disarmed their military. As if they had been been waiting for this, the Tyran activated the few installations that had survived their war against the Precursors, and created a spore form of the Koozer-Ga parasite. The Precursor initially studied this out of curiosity, but later, the spores mutated the researchers into the terrifying Combat forms, which infested the entire planet on which the Facility was located.
the Koozer-Ga War
After losing contact with this planet, the Precursors investigated, but were also absorbed by the Parasite, who proceeded to use their ship to escape the planet and propagate across the galaxy. After the Precusors grasped the aim of the parasite, and prepared for war, It was too late, The Precursors were nearly overwhelmed, and they built and activated The Rings to deny the Parasite it's goal of annihilating all intelligent life in the galaxy. The Parasite would appear 2 more times, before eventually being eradicated entirely.
While proven examples of Tyran technology are not known or proven, it is believed the that Mantle Armor was a Tyran Construct, and that they had created a portal to Volingarde, the Dragon realm of the dead.