Vagaari

The Vagaari are a bunch of aliens from the Unknown Regions who were the enemies of the Chiss Ascendancy. They had this gigantic empire spread out through multiple systems, among the species that they conquered were the Geroons. They had advanced gravity well technology that they used to much success against their enemies. Then one day, they ran into Outbound Flight and got pwned thanks to the POWAH of Thrawn. Years later, upon discovering the crash site of Outbound Flight, they attempted to get their revenge on the survivors but failed. When the Yuuzhan Vong invaded the galaxy, they joined forces with them and were destroyed when Beagle Force devoured the entire Vong invasion force, thus ending their threat, for now.