The IKS is a very rigid collection of five planets inhabited by Klingons who fled what they call "the Great Plague" in the late 2260's. This refers to the cure to the Augment Virus, which they saw as undesirable. In effect, they are TOS smooth-headed Klingons. They reject any contact with other Klingons, considering them unclean, and worship the old Klingon gods. They are unaware that the cure is no longer effective, and if they find out about the Federation's attemp to modify cure for the Sphere Klingons, they will do anything they can to stop it. This, of course, means that they will be implacable foes of the crew of the Rising Sun.
with typical modern Klingon male
Klingons of the Imperial Klingon States are typically of the smooth-headed variety familiar to the Federation of the mid 22nd century. They have a Rigidly militaristic totalitarian culture, with women relegated to secondary status. They are not as concerned with "honour" as their modern Klingon bretheren in the Empire who they disparagingly call "Imperials." They sometimes refer to themselves as Fusions, or Augments, and are much as John Ford described them in his works.
The Imperial Klingon States uses older technology in front-line service. Although obsolete, they are still effective and deadly. IKS disruptors do not have a "Stun" setting. IKS Klingons habitually use a shortsword rather than a bet'leH or dk'tagh although use of the bet'leH is still taught.
The IKS fields a number of older ship designs. In total, they have a fleet of about 250 ships, including about a dozen K'T'Inga class battlecruisers, their newest ship, which was just coming into service when the political separation from the Empire occurred. They also have the only remaining three L-13 battleships, a formidable foe in a fight, but only capable of WF 5.0.
A number of older-style shuttlecraft are also in service. The Type 3 and 5 are representative...
Korak, the Klingon chief god, is a stern father-figure and war god similar to the Human god Mars. The Fek'lhr is the closest thing they have to a devil, is the god of Evil. He is envisioned with ridges like the "Imperial" Klingons. The IKS pantheon consists of about 100 different gods and goddesses. Klingons of the IKS are matter-of-fact about their dealing with the gods, without much in the way of ritual.
Klingons in the Imperial Klingon States are less concerned with honour and ritual than their cousins in the Empire. Off duty, they are remarkably laid back and enjoy life to the fullest. Many could even be considered hedonists. They are capable both of considerable charm and duplicity. However, when crossed, they are capable of being every bit as vicious and violent as are the "Imperials."