The Kascn were an advanced empire first discovered on the planet closest to the Galactic Core. They were ruthless killers, eliminating every form of life except their own on their planet. When they first discovered space travel, they did the same to the surrounding planets as well, eventually conquering even the Grox. When the Central War entered Kascn territory, they immediatly sent in a fleet of ships, destroying the entire Dylise fleet, and sending a clear message to the Pholan. After several attacks on the now quite large Pholan Empire, the Pholan decided that somthing must be done about this. This led to the formation of The Pholan Alliance, an alliance between several species for the sole purpose of ridding the galaxy of the Kascn. Eventually, the Kascn decided to enter the Galactic Core, and harnessed the power inside. They packed this energy into amazing weapons capable of destroying entire solar systems at once. These "Galactic Eliminators" were used this to nearly eliminate the Pholan Alliance.
No living creature has ever seen a Kascn, and probably never will, as you wouldn't be able to get close enough to see one without being in their attack range. They are believed to have been created by the Xarn (the same entity that created the Pholan), due to their proximity from the Galactic Core.