The Leviathan is an office block-sized vehicle with an impressive array of weaponry, Void Shield protection, and huge transport capacity. Its main armament, the Doomsday Cannon, has enormous range and will destroy most enemies in a single volley.
The Chaos Firelord is a bomber is excellent at destroying entrenched targets. Flame Cannon and Firestorm Bombs make a mockery of natural cover or fortifications, while its Twin Lascannon is useful for taking out enemy armour and aircraft.
A Questor Titan is well equipped to take down large numbers of enemy units with each volley it fires. Its Castigator Cannons are especially good at cutting through swathes of infantry.