The Warlock-class Star Destroyer Mark II is, as its name would imply, a second generation warship. Very little is known about the Warlock Mark I, but it can be assumed that there is a great deal of similarity between the classes. The Warlock II itself is a highly experimental model, and thus far only one of them is known to exist, the Warlock.
The Warlock Mark II is a unique warship in that it is a full 1,000 meters longer than a standard Star Destroyer. Despite its larger size, the Warlock Mark II mounts only comparable ship to ship weaponry. This can be explained by the vast point defense system that the Warlock Mark II boasts, using a full 170 Quad Laser Cannons and an advanced A.I. targeting computer to track and shoot down incoming warheads. This system is also effective against enemy starfighters, though it is somewhat less efficient.
By way of trial testing, the Warlock Mark II also boasts an experimental ablative armor. The armor provides protection equivalent to that on an Imperial-class Star Destroyer.
Aside from its size, experimental armor, and highly advanced point-defense system, the Warlock Mark II has one major advantage in combat: it's the first warship to mount and use a planetary-scale ion cannon. The cannon is mounted on the ship's bow, and all other weaponry must be inactive for it to fire. After firing, the cannon requires a recharge time of one to five minutes (depending on how many of the other weapons are active) before it can be used again.