Ah, Priestess...
You're still with us.
The Chief Guardian, also known as Groa, is a miniboss and a Spirit.
Acquisition
Chief Guardian can be found on the upper-left location from the "Cathedral Cloister" Respite.
Bloody Knight's Claws action is required to reach her.
Battle
During combat, Chief Guardian combines the attacks of guardians commonly encountered in other locations.
In melee range, she can swing her round blade at Lily.
When throwing her blade, she can throw it either from below so that it remains in close range and then travels over her head and behind when returning, or from above to medium range so that it moves straight to her when returning.
When Lily is too far away, she will raise her hands and throw the blade upwards to create a fiery vortex at Lily's position after a delay.
Spirit
The Chief Guardian sends out a bladed star that spins, replicating that of the Guardians found in various parts of the world, most prominently that of the Catacombs.
At levels 1-3, damage scaling is 140%.
Starting from 4th level, bladed star flies twice along its path, dealing 75% damage each time it hits.
At 6th level, it flies three times for 60% damage with each hit.