The Black Shark is the OEM's first attempt at a gaming smartphone. It was released with Android 8.0 (Oreo) out of the box, and had not had a major update since. However, it now has access to an OTA upgrade to Pie (9.0).
https://www.notebookcheck.net/Xiaomi-updates-the-first-gen-Black-Shark-to-Android-Pie.435106.0.html