Unbeknownst to anyone , Unalaq was working to release Vaatu from incarceration in the Spirit World .
Unbeknownst to anyone , Unalaq succeeded in this task before fusing with Vaatu to become the first and only Dark Avatar .
Unbeknownst to anyone , Unalaq was working to release Vaatu from incarceration in the Spirit World , and succeeded in this task before fusing with Vaatu to become the first and only Dark Avatar .