Correction: AF3 The Circle of Time
After you dig the ring out in Xacabard you need to return to Port Jeuno and speak again to Imasuka near the Qufim. ...
I made it alone all the way from sandy here at lv 21. Understand that once inside the grotto, you're best to run like heck and fight nothing. If you stop, you will likely die. In any case, it can be done