(My own army!) So you saw those wicked looking warjacks with all those zombies, ghosts, thralls and pirates(yes pirates!) walking behind them. That faction is called Cryx.
When Dragonfather Toruk went on a rampage against his brothers and the new land of Immormen, many saw him as a true source of power, so they pledged their alleigance to him. Then Toruk killed his new followers. Then he rebuilt them from black iron or used his draconic powers to raise them up. His first followers were called, Liches. So they killed, burned, maimed (they did have a drgon lord by their side, and they were skilled combatants) many towns, and rose them up again. The best liches were made Lich Lords. And so in the name of Toruk, they aim to crush all of Immormen.
Cryx play like a glass cannon. In combat, they hit like a ton of bricks but if the combat drags on for more than two turns, chances are they will be killed. Cryx are the fastest army aswell, so getting into combat is really easy. Each unit has a special rule, be it Undead or Pathfinder. Cryx have very good warcasters, their average FOCUS is often the highest other armies get. But they need it. To truly win, they have a vast arrange of crippling debuffs and amazingly versatile buffs and damage. Another cool thing, is the fact that they can reap souls and use them to get stronger. Cryx have the most arc nodes in all of WARMACHINE. Every light warjack except for one, has an arc node to sling spells from all directions. Pirates are great tools to play games with your opponent or cripple them for a warjack. Cryx warjacks are actually known as "Bonejacks"(light) and "Helljacks"( heavy).
Unfortuneatly, Cryx are not liked by opponents due to their rules now note, in WARMACHINE, no army is broken, but Cryx just take your best units and make them useless or use them to their advantage. Cryxian warjack armour is the lowest of all jacks, so they rely on their high DEFENCE to keep them safe but when hit, prepare to lose a vital weapon or lose it all together. Relying on spells often mean that Disruption can ruin the armies plans. Plan a plan B, if you play something wrong, it could blow up in your face.
So if a tactical, fast, dead army appeals to you, then welcome fellow Lich.