Garuda race option (Aarakocra re-skin)
by Marc SaindonAdding a bit of fantasy elements to Sind, you have the Garudas, or Eagle-Folk. They are a deeply religious folk, often pursuing careers as Paladins (maybe call them "Maratha Warriors" for a less West European name) or Clerics. They are part of the upper castes, although not frequently encountered, as they live on mountain tops, were they run shrines.
For adventures, the Garuda promote the desires of their gods and follow many quests. They also have an ancient rivalry with the Nagas (Serpent-Folk), and this blood feud has no end in sight (even Fallen Garudas still hate Nagas). They also scout to warn against dangers from Hule.
During the Hulean invasion, the Garudas some opt to withdraw to Darokin, as their more straightforward, honest and direct approach make them inefficient in the type of guerilla warfare needed to resist Hule. Others keep to their mountain tops, which are difficult to reach and have little strategic value for Hule. During this era, the Garudas will undergo an important cultural shift, which the PCs could influence.
Alternatively, you could make them a re-skin of the Aasimar (which normally don't exist in Mystara).
(Image from: https://www.deviantart.com/pursuerofdarkness/art/Commission-Garuda-750967135)