Before I post the al-Kalim bio, I need to make a couple of premises.
First of all, by all we read in GAZ2, at the time of that gazetteer al-Kalim is considered an immortal prophet, BUT in truth he is still on his path of the Dynast. This means that by AC1000 al-Kalim is not yet immortal. Yet his priests receive spells!
In WotI however, we see that al-Kalim finally made it and he's 3rd level. Since WotI is set between AC 1001 and AC1003, it can be gathered that al-Kalim succeeded in his path during this timeframe. I chose Ac1001 as his ascension date.
The mystery about the spells to his followers still remain, and can be solved in four different ways.
1. The Old Man of the Sea, as his sponsor, gave them their spells. This is unlikely IMO, because no other immortal candidate ever benefited from this treatment, and Protius is known for being rather detached even from his followers.
2. The Immortal Guardians gave them their spells. Since the Eternal Truth is known for being both a polytheist and philosophic faith, it is very likely that al-Kalim adopted this kind of cult to have other immortals grant spells even to his priests while he was still on the path of the Dynast. More likely that option 1.
3. The Eternal Truth is also a Philosophic Faith devoted to Law, so these clerics were granted powers by taping on this ethos. It is one of the choices that basic set allows for clerics, so why not, given the way Mystara works and the way the Eternal Truth (as Lawful Church) is structured.
4. al-Kalim created an artifact that gave his followers divine powers during his path towards immortality. Highly difficult to do, but hey, since he's going to become an Immortal, not impossible!
That said, here's the write-up for Suleiman al-Kalim.
al-Kalim
by Marco Dalmonte(The Peacemaker)
Patron of Ylaruam, Holy Prophet of the Eternal Truth, Patron of Tactics and Warfare
Level, Alignment and Sphere: 3rd (Initiate, LN), Time
Symbol: the silhouette of a palm tree that grows in the desert with a rising moon on the background
Portfolio: the Eternal Truth (obedience and respect for laws, honesty, justice, honour, goodwill, wisdom, prosperity), tactics and warfare
Worshipped in: Savage Coast (Gargoña and Saragón), Known World (Darokin, Ierendi, Ylaruam)
Appearance: an elderly human patriarch wearing poor clerical robes, with a firm outlook, wise and intelligent eyes and a long white beard. His second manifestation form is that of a youthful dashing desert warrior with a hawk's nose and a well trimmed black beard, riding on a perfect Alasiyan stallion wielding his scimitar.
History: born in AC800 in one of the Alasiyan tribes of the desert, during the Thyatian and Alphatian occupation of IX century Suleiman al-Kalim spent his youth trying to reconcile the way of the desert warrior with the old teachings of the dervishes who brought him up. In his adulthood he became a wise warrior-priest, and later was hailed as the leader of Alasiyan insurrection against the foreign conquerors. Using bright guerrilla tactics and his innate leadership skills, al-Kalim was able to unite the tribes one after the other, and with their help, he started a liberation war against the Alphatians and the Thyatians that lasted for more than a decade. In the end, the Alasiyans were able to throw the invaders out of their borders and established the United Emirates of Ylaruam in 831 AC, a confederate nation where all the tribal chiefs are led by a Sultan, a position held by al-Kalim. In 835 AC al-Kalim began a religious pilgrimage with his faithful companion Farid that took him outside Ylaruam and up to the underwater mountain where he met the Old Man of the Sea, who became his patron and sponsor on the path of the Dynast. When he came back to Ylaruam, al-Kalim started preaching to his followers the teachings of a new faith, the Eternal Truth, which Farid collected in the holy book named Nahmeh, a collection of wise parables and just laws. The Eternal Truth was based on two main pillars: the Dream of Justice and Honour to unify the tribes and make them stronger in order to withstand the eventual disappearance of al-Kalim, and the Dream of the Desert Garden, the project to make the desert a more fertile land that could rely upon itself and diminish the foreigners' influence in Ylaruam. al-Kalim retired from public life in AC 860, and later made up false news about his death to proceed on the path of the Dynast. He finally reached immortality in AC 1001, after securing his dynasty on the throne of Ylaruam.
Personality: al-Kalim is at the same time a merciless warrior and a merciful sage, a possessed dreamer and a realistic scholar. He is tolerant towards diversity and foreign customs, but he can prove stiff and unforgiven when it comes to the safety of his protégés and followers and when his teachings are scorned. His followers act much the same, with the zealots reaching peaks of blind intolerance. He preaches unity among his faithfuls, the sanctity of life and the protection of nature (in particular of water as source of life), all teachings that come from an existence led in places where death and drought are hated life companions. For this reason all Alasiyans follow the Eternal Truth. al-Kalim is a loyal ally of Protius who sponsored his ascension, and he feels in debt towards the Old Man of the Sea, since he has not yet kept his promise to make the Alasiyan Desert a lush garden in his honour. He is in perpetual conflict with Zugzul and Ranivorus, which brought and still bring chaos and destruction among the Ylari with their machinations and the use of their followers (Magians and Gnolls).
Patron: Old Man of the Sea (Protius)
Allies: Protius
Enemies: Ranivorus, Zugzul
Classic D&D Stats:
Followers' Alignment: Lawful or Neutral; Clerics must be Lawful.
Favoured Weapon: Scimitar (allowed all bludgeoning weapons)
Clerics' skills and powers: the clerics of al-Kalim have a wider list of spells since they get access also the druidic spells of 1st and 2nd level
Paladins' skills and powers: Lay on hands (cures a number of HP equal to double their level)
D&D 3E stats:
Domains: Time, Law, Water, War
Preferred Weapon: scimitar
Sources: GAZ2, GAZ4, WotI, SCS