Religion plays a big role in the world Diablo 4, because light and darkness are constantly in trouble. Sister Octavia is a priestess from the Cathedral of Light who helps the people of Kyovashad fight against the evil that has overtaken the Sanctuary, but Sister Octavia also needs help with great knowledge and skills in exorcism.
Sister Octavia has a three-part questline that is very rewarding to complete. There’s not only gold and XP to be had, but also hoards of herbs and elixirs, regional renown, and a piece of rare Focus gear.
The disease of soul searching
You must reach level 20 before you unlock the Soul Disease Quest in Kyovashad.
To pick up the Soul Disease quests, you need to talk to Sister Octavia in the residential area northwest of the Purveyor of Curiosities vendor in Kyovashad.
Octavia will reveal that Peter’s son is possessed by a demon, and he needs your help to exorcise the demon. Sister Octavia is independent in her own right, because even though the priests of the Cathedral of Light burn victims of demonic possession, Octavia would rather save the victims than torture them to death.
Entering the Frigid Cellar
In the main room of the Frigid Cellar, you will see Peter’s son lying on a bed. Octavia will give it to you The Holy Chalice and I ask you to place it by the bed while referring to his prayer book.
Placing the holy chalice on the ground will start the exorcism and Octavia will begin to recite a prayer.
The child will begin to levitate and Xul’goth will become agitated, summon several weak Carver mobs to attack you. The exorcism will not continue until you kill all these mobs.
How to banish Xul’goth from Peter’s child
Xul’goth will be summoned after you kill all the mobs in the basement. Xul’goth, Chilled Touch, is an elite enemy that has the Summoner and Cold Enchanted perks, allowing him to freeze you on contact and summon mobs during combat.
Xul’goth can be easily killed, but you’ll want to watch out for his powerful attack as it deals a lot of damage. Although it is a slow attack, you won’t be able to avoid it if you freeze.
Claiming your reward
After you defeat Xul’goth, Peter’s child will be freed from the demon and you can find Sister Octavia for the reward outside the basement.
Searching the depths of despair
You will have to leave Kyovashad for the Depths of Despair quest to become available, so either fast travel or complete the quest and return to Kyovashad.
This time Sister Octavia needs your help track down Kvera’s husband Vasko.
The Depths of Despair can be picked up in the residential area northeast of the Purveyor of Curiosities vendor.
Upon arrival at Kvera’s home, she will explain that she suspects that her husband is possessed by a demon because of his unusual behavior and excursions. Kvera tied up Vasko in the basement before enlisting the help of Sister Octavia.
Enter the Sinister Cellar and kill the mobs which spawn at the entrance. After all the mobs are dead, you will hear Kvera’s scream above.
Exit the basement with Octavia to reveal that Vasek has escaped. Pursue Vasek and follow the trail of blood that leads you to Kyovashad sewage.
Make your way through the sewers
You have to work your way through hundreds Carvers, Carvers Overseers and Barbed Swarms until you reach Waste water basin. The tunnels have many paths, but most of them lead to the end of the sewers.
You once reach the waste water basin, talk to Sister Octavia to plan your next move. Octavia will give you a holy chalice to place next to Vasek and allow her to begin the exorcism.
How to banish Demothath from Vasek
Unfortunately, this exorcism does not go as smoothly as the previous one, and Vasek is killed in the process. You will have to kill Demothath, Baron of the Frozen Wasteselite enemy with accessories Chilling Wind, Frozen and Summoner, take this demon one step further in trouble.
Missiles will also not work when shooting through Demothath’s Cold Wind ability, but it is Demothath’s ability to summon three frozen orbs that deal massive damage and slow your movement.
The small area also makes it difficult to maneuver around these spheres. When Demotath summons frozen orbs, you’ll have them a short window to avoid the area of effect.
Claiming your prize
When you kill Demothath, talk to Sister Octavia outside the sewers. You can teleport back to Kyovashad to get back to the entrance faster.
Octavia will rewards you with Elixr Cachea good reward as Elixrs grant you a 5% XP boost and improve your defensive abilities in combat.
Faith In Blood Quest
You have to leave Kyovashad and come back again for the Faith in Blood Quest to appear.
To take the quest, talk to Peter, found near Kyovashad pointwho will explain to you that Sister Octavia needs your help.
Petr will give you a note from Octavia explaining that the wounds from Demothath have worsened and she believes that Demotath was able to escape death by using her as a host.
Meet Kvera at her home before entering the Sinister Cellar to find out how you can stop Demotath from taking Octavia’s sister.
Enter the ominous basement
After talking to Kvera, enter the basement and talk to Sister Octaviawhich will reveal to you that you must find a new holy grail if you banish Demothath from it.
Octavia recommends talking to Matvej, kelihar in the margraviatewhich will give you instructions for procuring a new holy chalice.
Matvej mejni kelihar of the border count
You can find Matvej by the pile in the center of Margrof. You trick Matvey into thinking you’re working for the Reverend Mother Right to get the chalice.
However, Matvey will reveal that in order to transform the Chalice into a Holy Chalice, you must perform a ritual that requires you to fill Silver goblet with bandit blood.
How to fill a silver goblet with bandit blood
To fill the goblet with bandit blood, go east to Western Tunnels and Vale of Foolas these areas spawn hundreds of thugs to kill.
We could finish Bound by Blood Quest in addition to filling the chalice with bandit blood to save time and gain more XP.
You can take over the task until conversation with Lacthanwhich is found I’m talking to the townspeople north of the burn.
When you fill the goblet, return to Matveywho will explain to you that as the final part of the ritual you must take a burning piece of wood from the logs and place it in the chalice.
Return to the ominous cellar in Kyovashad to begin an exorcism on Sister Octavia.
How to Exorcise Demothath from Sister Octavia
You begin the exorcism using Sister Octavia’s prayer book and the holy chalice. This will anger Demothath, causing him to summon Carvers to attack you. Carvers are easy to kill, but you’ll want to kill them explosive ice carvers before they reach you.
Kill the Carvers and then continue the exorcism by interacting with the holy chalice. This will cause Sister Octavia to freeze and summon Demothath.
Demotath has the same additions as his previous appearance in the Kyovashad sewersso use the same strategy and avoid the frozen orbs.
Claiming your reward
After defeating Demothath, meet Sister Octavia outside where she will be to give you her prayer book.
Sister Octavia’s prayer book can only be equipped Necromancer and Sorceress classes.
Next: Diablo 4: They come to three, quest flow