RG Veda

It's by CLAMP also. The characters in X, Tokyo Babylon, RG Veda, xxxHolic, Tsubasa Chronicle, and Chobits all...connect. The shows sort of overlap. 

Both have ancient emperors in a magic east land. the fate of this world also depends of a girl. sword wielding. 

Both are adaptations of CLAMP works. Both anime have similar concepts about destiny/revenge/changing ones fate. Both adaptations rush through a story that can't possibly be told completely in the time given, resulting in lots of cut content from the manga/original scenes that change the outcome of the story to fit into a shorter narrative.  

Mythical deadly beings, the ones loving/protecting them against all common sense, and how one's personal decisions impact the world's future. Both involve a beautiful, golden-eyed gender fluid main character (sexless in RG Veda, hermaphrodite in Kimera) which turned female in the english dub/sub, nevermind the story being played out in BL flavor. Despite their flaws and limited budgets, they're a short and decently compelling watch if you can't lay your hands on the manga or simply enjoy dark, exotic fantasy OVAs with vintage vibes and aesthetics. 

Action, drama and apocalyptic adventures by Clamp (loosely) adapted in glorious 90's style. While Rayearth is a retelling of the original story, RG Veda serves as a rushed, basic introduction of the manga. They can be quite confusing for those unfamiliar with the main series, but if old school, bishounen-filled, dark fantasy OVAs are your thing, it's likely to appreciate both. 

both are romantic fantasy adventure shoujo about a weak main character who's being protected by very powerful and beautiful guardians. 

both are shoujo action 2 episode ova with a slightly romantic shounen ai main couple with huge age gap. 

Expect wizardry and medieval fantasy in both