Online:Meridia's Brilliance

Quick Walkthrough
#Find Priest Direnna, Acolyte Hjolt and Roligmolf near Kilkreath Temple.
#Speak with Priest Bavian at the Pilgrims' Lodge.
#Enter Kilkreath Temple and search for the missing priests.
#Find the  .
#Retrieve   from the catacombs.
#Speak with Priest Bavian outside Kilkreath Temple.

Detailed Walkthrough
Upon approaching Kilkreath Temple you meet a distraught Priest Isonir. The temple was hit by a Harrowstorm causing many of the pilgrims and priests to be transformed into Harrowfiends. he asks you to find Priest Bavian in a nearby cave and assist her with rescuing any survivors.

Head north to a cave just west of the Kilkreath Temple Wayshrine and talk to Bavian. She will ask you to check on a group of pilgrims and priests taking shelter in some stables to the east and then meet her at Pilgrims' Lodge to the west of the temple. Head east to the stables and you will find an unresponsive Priest Direnna and the body of Roligmolf. Examine the body of Roligmolf to get his   and examine the catatonic priest. Head inside the Stablemaster's House to find a frighted Acolyte Hjolt. Speak to him and tell him to head to the cave where the rest of the survivors are.

Head south to the Pilgrims' Lodge. Inside you will find Priest Bavian trying to use Meridian Magic to heal a catatonic Acolyte Eivina but it has no effect. Speak to Priest Bavian and she will ask you to accompany her to Kilkreath Temple to find High Priest Varkour.

Head east and enter the temple. Head down the ramp and examine Acolyte Larilvor to retrieve his Meridian Medallion. Head north through the eastern corridor and speak to Acolyte Croble through a window on the right side of the corridor. After talking to him he will be attacked by a harrowfiend forcing you to leave him behind a continue your search for the high priest.

Head north and up the stairs to the right to find Priest Triev standing over the body of Acolyte Molozu. Triev explains that her acolyte had transformed and she had been forced to kill him in self defense. After talking to her Priest Bavian will notice Priest Ahmin running into the vestry and run after him. follow them into the Kilkreath Vestry. kill Priest Ahmin who has been transformed into a harrowfiend and speak to Priest Bavian.

The priest explains that she believes that the high priest has taken a defensive position in the catacombs with the relic  . She believes the relic could be used to channel Merida's Light to purge the temple of the corruption plaguing the temple. She explains that you will have to retrieve the key to the catacombs from Chamberlain Marck.
thumb|right|Retrieve Meridia's Brilliance
Head through the door to the south to the Kilkreath Meeting Hall down the corridor and to the east and head across the balcony and through the door to the Chamberlain's Sanctum. Follow the corridor to it's end and kill Chamberlain Marck who has transformed into a harrowfiend and retrieve the catacombs key form the chamberlain's key box. Exit through the door to the right.

Jump down to the floor below and speak to Priest Bavian then enter the Catacombs. Follow the corridor south and then east into the door to the Lower Catacombs. Defeat High Priest Varkour who has transformed into a harrowfiend and retrieve Meridia's Brilliance. Exit the temple by the ladder to the northeast. head back to the cave where you first met Priest Bavian and give her the Meridian medallions that you recovered along with Meridia's Brilliance to Finish the quest.

Notes
If completed alongside The Gathering Storm, Fennorian will provide additional dialogue and insight throughout the quest.
 

Quest Stages