[This is not told from Kilomar's perspective.]
K'Hlairo is the Tondi Tohr'Kreen leader of the Dark Circle, and his kingdom is based on Athas. He commands a large number of elite, nomadic Tohr'Kreen, Thri'Kreen, and Trin. He is a 30th level priest, and prefers to be called Kh.
Kilomor is the second in command of the Dark Circle, but as he is the most active one he is often percieved to be the leader. He is a 15th/21st warrior/mage orc who is a Legendary (Elder) goblinoid with formidable Wild Talents and a gigantic army. He is also much more active in the Planes than Kh, and he was the one who created the Demiplane that would later serve to be the Dark Circle's meeting ground. He also leads his own sect in Sigil, but his main kingdom is in Toril. He is 3200 years old (he has the Long Life blood ability), he'd be 4100 except he spent the last 800 years in a sort of stasis void (created by the elves) after being captured alone, by a large elven force. (They couldn't kill him at the moment because he was using his newly discovered true dweomer Kilomor's Hearthide.) However, recently a child Elf freed him because he promised him all sorts of gifts [when he sometimes strolled around the Thousand Death's city, he saw an Orc mother promising her childs baubles and such, that's how he knew - ed.] It is not know what happened to the child, or the elves who captured him, after he was released.
Kirdij is a 28th level warrior Aarakocra, without peer in the Long Sword business. He is the strong arm of the Dark Circle. He does lead a tribe of Aaracockra which is based near the Wondrous City of Greyhawk. He is betrothed to Jillenuq.
Jillenuq is not a true member of the Dark Circle, but is allowed in meetings and missions because her husband, Kirdij, insists it. She is a 29th level swanmay bard who co-leads Kirdij's tribe.
Xat'chel'd is a recently joined member, however he is very powerful. He is a 28th level psionicist Lawful Neutral Psionic Archlich who escaped from Ravenlost 190 years ago. Since the Dark Circle is known even on Ravenloft, he searched out for Kilomor (who he incorrectly thought was the leader), and asked if he could join. Kilomor went to Athas to get the approval from K'Hlairo. Heavily psionic himself, Kh let him join. Xat'chel'd is now a good friend of ElfDeath (a.k.a. Morsilvanus).
Ryykax is a sub-member of the Dark Circle, but is unlike Jillenuq in that he is actively working toward becoming a true member. He is a 12th level priest hobgoblin, the apprentice of Kh. He is a military genius, and has a goblinoid army only rivaled by the Thousand Deaths himself.
Morsilvanus is also a sub-member, but could probably take on the entire Dark Circle and win. He is an Age Category 11 Shadow dragon who is a Legendary creature (Great Elder). He is a direct general to Kilomar and often trains his armies when Kilomor himself cannot do it.