I had some thoughts about doing a Turkish nation for each age (having studied quite a bit of Turkish history for my own mod nations-and having a little Turkish blood ancestry, as well):
Early age: Hittites/Cimmeria/Lydia, Cappadocia, early Anatolia, the Gokturks (Anshina), the Seljuk dynasty, and the Hun (who were partly Turkic) invasion. The mythological focus would be on Turkish shamanism/animism (Tengriism, and it's polytheistic predecessor)-what can be separated from Confucianism, and Altaic mythology. Starting sites might include: Khan Tengri, the Noin-Ula Kurgans, Derinkuyu (might give an Earth gem, and also, the Early Age home Province might be a cavern). Magic Paths might be: Air, Earth, Nature, Death.
Middle Age: Khazars through the Mongols/Golden Horde (again, an alliance of Turkic and Mongolian/Asian peoples). Altaic and Tengri mythology, heavily influenced by Asian/Confucianism influences. Starting sights: The Silk Road, Khara-Khorum, Khara-Khoto, Khara-Balgas. Path suggestion: Earth, Air, Blood, Fire, Death.
Late Age: Amir Timur (Timurlane)'s Mughal Empire. Mythology would range widely, from Islam-Alevi (Ocakzades, musical magic) through Burkhanism.
Starting Sites: Samarkand, the Silk Road. Paths Suggestion: Earth, Air, Fire, Astral, Death.
I'd be happy to help you research this, if you really do intend to make a mod nation (or three in succession
). I've actually done some prep-work on a mod nation of MA Aboleths, heavily flavored by the Mamluk empire-also of Turkish origins.