A Shipkiller is an Earthfleet category of ships, which includes the Sergenious, Samurai, Pegasus, Raven and Wolfpack classes, that is designed entirely with the intention of being a small, light, inexpensive, yet fast, agile and powerful starship capable of going toe to toe with a full size battlecruiser, some of which can be over 20x's its own size, and winning the fight every single time. The capabilities of the various classes within this category range from offensive systems capable of going up against light and medium battlecruisers and battleships, as in the case of the Sergenious and Samurai classes, all the way up to heavy battlecruisers, battleships and light to medium dreadnoughts, as in the case of the Pegasus, Raven and Wolfpack classes. In each case, the five different classes of shipkiller were built with a different roll to fulfill, which focus primarily around which ships within the galaxy, and most especially among The Nine Ancient Races they would be used against should the need arise. And, while the later Mythos class supersedes them in the primary defensive roll of protecting Sol Space, they still play a very important roll that the Mythos, and similar ships, are unable to fulfill, despite their impressive firepower and capabilities.
The various shipkiller classes either support or feature a wide variety of offensive and defensive weaponry, including a variety of torpedoes, plasma cannons, Fluidic Armor, screamers and other tactical equipment. The ships themselves don't have any specific weaponry or defensive systems, aside from Fluidic Armor, that are unique to themselves. But rather, for purposes of simplicity and ease of resupply, share many offensive and defensive systems and technologies that are common to all of Earthfleet. Some systems, such as their multi-layered shield systems, and Reactive Shielding, while common to the rest of the fleet, are generally more advanced and often unique in their operation and functionality when employed on the shipkillers.