Bring 1 Qiraji Ceremonial Ring, 2 Onyx Idols, 5 Stone Scarabs and 5 Crystal Scarabs to Windcaller Yessendra in Silithus. You must also attain Honored reputation with Cenarion Circle to complete this quest.
The rings worn by the Qiraji lieutenants are rumored to grant them formidable abilities. The corrupted gems that adorn them could, in theory, be swapped out with more pure materials to create uncorrupted versions of the rings.
The gems that adorn Qiraji idols would work quite well, as their quality is superior.
Bring me the ring and idols and I'll create a powerful ring for you, <class>.