Other Immortals
by Marco DalmonteNinfangle: this comes from IM1, where it is mentioned a certain "Net of Ninfangle", a powerful artifact. I've speculated him to be the first rakasta immortal after Bastet's ascension, a patron of Hunting, Adventure and Bravery among rakastas. He's better known among them than Bastet (due to her later moving away in another dimension before coming back to Mystara) and he's probably the immortal worshipped by the "wilder" oriental rakastas of Bellayne. He's also known as Nin fang-le
The background was entirely made up by me, so you're free to do with it whatever you want.
Ninsun: mentioned only in old Gold Box as creator of one of the artifacts. She's from Sumerian mythology, the mother of Gilgamesh IIRC. In my background, she's the first true Oltec Mage, creator of the Rainbow Path (the magical means used by Oltecs to settle all around the world) and patroness of Oltec scholars and wizards as well as associated with fertility and harvests. She's especially worshipped in Bellissaria and Minaea (where the descendants of the Oltecs are supposed to live) and in some places around the Arm of the Immortals..
Luca: Luca is a common enough name in Italy, it's our version of Luke. One of my players' name is Luca, so using this as the name of an Immortal didn't sound right to me. For this reason I followed the advice of another fellow gamer (I think it was Lo Zompatore) and took the name as an acronym for Last Universal Common Ancestor (or LUCA). LUCA is therefore the patron of all proteans, the first and simplest lifeform on the Multiverse to have achieved intelligence and earned immortality. Problem is, it didn't develop any further and stood true to its original form and interests. LUCA is not really worshipped anywhere, and its sole goal is to engulf the whole multiverse in protean-materia... pretty weird uh?
Simurgh: this comes from Master set, as Ripvanwormer already explained. In real world Persian mythology, Simurgh is a gigantic, winged monster in the shape of a bird; a kind of peacock with the head of a dog and the claws of a lion. Its natural habitat is a place with plenty of water. According to legend, the creature is so old that it has seen the world destroyed three times over. In all that time, Simurgh has learned so much that it is thought to possess the knowledge of all ages. In my version of the legend, Simurgh is indeed an ancient being, not even the Immortals know if he has ever been mortal before attaining immortality. Even if he has a homeplane, he is rarely seen there and he vanishes for centuries before reappearing, usually heralding some major catastrophe. Khoronus is his staunchest ally and they cooperate to help mortals and civilisations that survive the catastrophes that befall them without altering the timeflow. Khoronus suspects he is native of Temporal Prime (the dimension of time itself), while other immortals think he may be a messenger of the Old Ones, sent in the Multiverse to correct mistakes when they appear. What is certain is that, despite all his interventions in history and his quests, its power level as an immortal never changed ever since he appeared in the Multiverse millennia ago, and that tells him apart from the rest of the Immortals.
Qywattz: he's the patron of the Neh-Thalggu, the Brain Collectors' god mentioned in that episode of the Voyages of the Princes Ark where Haldemar meets one of these creepy creatures under the swamps of Ator. Now, given the brain collectors' nature and habits, I've made him a different kind of Immortal, totally alien to human and demi-human standards, originally born in the Nightmare Dimension. His sole purpose was collecting all knowledge in the universe, that's why he began kidnapping the wisest creatures of all kinds and storing their brains in his "library". To help him in his quest, he created a new breed of creatures with powers apt to this kind of job: thus were the neh-thalggu born. That's why he isn't worshipped on Mystara, solely by his neh-thalggu' s followers. As for how he attained immortality, he's the Mystaran version of Vampire: The Masquerade's Tranmere, in that he simply diablerised another immortal. He imprisoned Ouranos and literally sucked all his immortal essence until he became immortal. Ouranos probably still exists somewhere inside of him, although trapped and powerless to free himself.