How to flash OctaviOS v2.9 for Begonia

Recommended

Proper Backup

Recovery:- Begonia Recovery Project 3.5.2 - Unified 3.0 or Any MIUI 12.5 based recovery

Already on 12.5 based rom?

Simply clean flash no need to format data
Flash Disable ForceEncrypt After flashing rom

Otherwise, follow the guide given below

Instructions:

1. Flash latest fastboot MIUI 12.5

2. Flash latest MIUI 12.5 TWRP recovery

3. Reboot to TWRP recovery.

4. Flash latest OctaviOS build & Gapps then format data

5. Reboot and enjoy.

(Optional:- Flash Disable ForceEncrypt after format data if facing Encryption issue after rebooting to recovery)

Important links:

MIUI 12.5 fastboot Rom: Global MIUI or Indian MIUI

MIUI 12.5 TWRP recovery: Latest TWRP For PE/PPUI

Note: It is recommended that you flash Magisk and other mods after the first boot.

Thanks to @ZIDAN44 for flashing instructions and Thanks to @SahilSonar for 12.5 bringup :)