Rank 4: Iron Warriors
Like most traitor legions, the Iron Warriors no longer form a unit, but consist of scattered packs. However, they have some advantages over many other Chaos Space Marines:
Iron Warriors do not believe in mutations, so they do not necessarily rely on the blessing of a god but enhance their bodies cybernetically. Their Primarch Perturabo is nevertheless now a Chaos Prince of the Undivided Chaos.
Warsmiths lead individual packs and often gather a large number of fighters under them, leading to a relatively organized fighting force.
Iron Warriors like to use Titans that the Imperium also has in its arsenal:
The Iron Warriors are excellent technicians with expertise in building war machinery and especially siege equipment. This makes them particularly dangerous, as their Daemonsmiths have mastered the art of merging demonic power with machines.
In combat, they use Chaos Titans more frequently than any other, massive walkers with heavy weapons and pretty much the heaviest war machines that can exist on a planet. This alone gives them enormous strength.