I'm looking for high-quality albums that incorporate a lot of non-Western folk traditions into metal. I'm familiar with Angra, Orphaned Land, Pentagram/Mezarkabul, and Myrath. I'd really like to see if there's anything from, say, South Asia or Sub-Saharan Africa in this space. I'd also be interested in anything incorporating gypsy/Balkan music with horns (System of a Down does this to some extent, but they have so many irritating Americanisms I can't really listen to them).

Have you ever listened to SpiRitual? They incorporate interesting hindu melodies and themes...

https://www.metal-archives.com/bands/SpiRitual/54646

For sure check out https://www.metal-archives.com/bands/Odious/7642

Those two are new to me. Thanks!

Tengger cavalry, chinese/mongolian folk influences. Their founder died few days ago

Ah yes, that's a good one. I have a couple of their albums in my Amazon Music queue and need to revisit them. Intrigued.

Subterranean Masquerade of Israel is another one that has some good moments, especially the song "Hymn of the Vagabond" from their last one.

chthonic have some pretty interesting stuff, while sounding a bit like a taiwanese cradle of filth

Familiar with them. Wish they had more Eastern elements in their music; it's pretty good but also doesn't stand out from the pack as much as it could.

Rudra are good with a lot of South Asian sounds to them.
https://rudrametal.bandcamp.com/
Cult of Fire as well.
https://cultoffire.bandcamp.com/album/-
葬尸湖/Zuriaake are bad-ass Chinese atmoblack.
https://pestproductions.bandcamp.com/album/gu-yan-album
Darkestrah, epic black out of Kyrgyzstan
https://darkestrahofficial.bandcamp.com/album/manas
Nashmeh also might be worth checking out.
https://nashmeh.bandcamp.com/album/khonyagaran-e-pars

Oh, and how could I forget Arkan https://arkan.bandcamp.com

P.S. I assume you've heard Sepultura "Roots" and "Against"

Mongol
https://www.youtube.com/watch?v=Cjy49sKxB7A

Narajanam
https://www.youtube.com/watch?v=77AzXKXpT2I

Kartikeya
https://www.youtube.com/watch?v=pMh4Y18anNI

Thanks for the recs, all, and keep 'em coming. I have a lot of listening to do.

You should definetely check Dishearten. Kind of melodic black metal with Middle Eastern / Anatolian influences.

Snowsedim play some pretty interesting Chinese folk metal

Honestly it would be awesome if there were more Brazilian bands that took the same type of tribal elements Sepultura use on those albums but combined them with actual metal.