In the same vain as the Imperial-II and Victory-II Star Destroyers; I made a "Zeta-II" based upon the Zeta-class Star Destroyer designed by  MarcusStarkiller.

Zeta-II Class Star Destroyer
Like the Imperial and Victory class Star Destroyers before them; the Zeta Class Star Destroyers of the Imperial Navy went through periodic upgrades to their specifications across the rise of the Galactic Empire, and the subsequent Galactic Civil War. The Zeta-II Class in particular was initially commissioned by Imperial Sector Moff Karla Veraaj of the Gaulus sector; the Zeta-I having proved an exceptionally valuable and versatile resource in her campaign to pursue the sector’s rampant smuggler and pirate operations given the relatively limited numbers at her command. The Zeta-II, unlike some of the pet projects pursued by Imperial political officers had many of its improvements based upon extensive field testing of the Zeta I under Moff Veraaj’s fleet commanders, with the first completed; the ISD Relentless Banshee becoming the flag ship of Moff Veraaj’s fleet upon its completion.
A key requirement of the Zeta-II was to retain the unique capability of her predecessor; that of not only carrying fighters, shuttles and other strike craft, but two Assassin-class corvettes. The large specialist hangars however proved vulnerable to boarding action by particularly daring enemy pilots, the first and most immediately evident addition to the vessel was thus a dorsal ridge; which not only reinforced the corvette hangars themselves, but adds additional turbo laser and laser cannon batteries specifically to cover the approach to her dorsal hangers. The hangars are further reinforced by being more heavily integrated into the vessel’s superstructure; with a large tractor beam array added just below the command deck to allow for rapid retrieval of her corvettes in the event one or both have been crippled by enemy fire.
A second major structural addition to the Zeta II is the addition of an aft-facing “cape” behind the vessel’s superstructure and above her engine housings; similar to that found on much larger Imperial war ships like the Executor class. This serves as additional protection for the engines, as well as additional armor for the vessel’s superstructure, and a location for point-defense laser cannons and turbo-laser batteries. This design element was chosen due to common wisdom among smugglers and pirate gangs that Imperial warships always had an aft blind spot that could be exploited. A final major addition to the vessel’s effectiveness is a single gravity-well-projector unit located on her ventral bow; while it does not allow for the coverage of a dedicated interdictor platform such as the Immobilizer-class cruiser or Eclipse-class dreadnought; it is ideal for preventing pursuit targets from escaping into hyperspace. The addition of mass and power-consuming systems forced a minor upgrade to the Zeta-II’s power grid and reactor, shortening her operational time between servicing, but this minor drawback was considered well worth the increase in effectiveness.
A final alteration to the Zeta-II is not structural, but found within the ships embarked compliment of craft and troops. In standard configuration; the Zeta-II abandons Imperial tradition and carries no ground-assault walkers or prefabricated garrisons; instead using the space to carry additional dropships, fighters, and dedicated ship-to-ship breaching pods. These changes in the vehicle pool, along with a compliment of Imperial Storm Marines are designed to further specialize the Zeta-II in its role as a swift, space-borne hunter of pirates and rebels alike.

UPDATE: some additional texture work done by  MarcusStarkiller