The Only Cure

Background, Your mom gives good Job! XD
"A Khajiit named Kesh has offered to help me commune with Peryite. He asked me to acquire a deathbell flower, flawless ruby, silver ingot and some vampire dust."

- The Dragonborn

Overview of my massive hairy ass! XD
Obtained in a random encounter with one of the afflicted or by manually walking to Kesh at the Shrine to Peryite(must be level 12 or above).

Given at the Shrine to Peryite by a Khajiit named Kesh. He tells the player to speak to Peryite, they must:
 * Obtain a Silver Ingot
 * Obtain a Deathbell flower
 * Obtain some Vampire Dust
 * Obtain a Flawless Ruby.
 * Give all of the acquired items to Kesh
 * Inhale the fumes
 * Kill Orchendor
 * Report Orchendor's death to Peryite

Walkthrough
Collecting the ruby is by far the hardest part of the initial task. There are a few methods you can try in order to get one for this quest. The Silver Ingot and Vampire Dust can easily be obtained by doing the warrior questline. The members of the The Silver Hand often carry these.
 * You can go to Mistveil keep in Riften and talk to Harrald who will give you the job to retrieve his sword from Balimund. He will then reward you in a random gem combination, if you don't get the flawless ruby on your first try just reload the most recent save and return the sword again until you get it.
 * A Flawless Ruby along with other precious gems can be found in a broken boat in the river southwest of Sky Haven Temple. They are sitting in the boat under the seat near the strongbox but not in it. There will be at least one flawless gem, but a flawless ruby is not guaranteed.
 * Another alternative method can be to mine for one randomly at the Sanuarach Mine. It is advisable to save prior to attempting this method, same as retrieving Harrold's sword in Riften as mining a gemstone is random. This mine is in the town of Karthwasten, to the right up the slope as you face out from the front door of the Karthwasten Hall. Karthwasten is to the southeast of the Shrine to Peryite, and you can see its marker from the Shrine. Once you get inside the mine, the path will split at the bottom to the left and right. Take the path to the right, go up the wooden ramp, keep left and go up another wooden ramp. At the top there are two Silver Ore veins on your left. If you keep going in the same direction and go up another wooden ramp, there are three veins on the left there as well. Remember to save your game before the first two, then mine all five veins at once. If you do not get a Flawless Ruby, reload your save and repeat until you get one.
 * Killing dragons is one way of obtaining this rare gem.
 * A fixed Flawless Ruby can be picked up from Shriekwind Bastion. Halfway through the dungeon, a single throne can be found in a blood-spattered room. Examine the floor near the unlit fire pit on the right for the ruby (ruby is not always flawless).
 * If you have Prowler's Profit, you'll be drowning in flawless gems of every type.
 * A fixed flawless ruby can be found during the Hail Sithis! quest. On the Katariah you can obtain it in the Emperors room (in the same room as his bed) on the table just in front of his bed. Another good method for finding one is, if you are in the Thieves Guild, take a fishing job from Delvin and a Shill job from Vex until you get one.
 * Also, the hidden chest glitch in Dawnstar, may contain one if you are a high enough level.
 * If you have become the guild master for the Thieves Guild, then you may get one in the tribute chest.
 * It is possible to find a flawless ruby on Mjoll the Lioness. Ask her to trade with you and take it from her inventory.
 * You should also be able to find two in your room at the college of Winterhold in the safe.
 * A Giant will sometimes drop flawless gems as a rare drop if you're a high enough level.

Once all necessary ingredients have been gathered, return to the shrine and inhale the fumes to speak with Peryite. He will give you a task to kill his current overseer, Orchendor, who has forgotten his duty to Peryite. He will also state that you will replace Orchendor as his new champion. Orchendor is a mage (fire/ice) who resides in Dwemer underground fortress called Bthardamz. It will be quite a challenge to find him there, because Bthardamz consists of a few levels and areas filled with Afflicted (minions of Peryite that Orchendor guides) and Dwemer Automatons. Try to follow the quest marker and check the local map often so you can keep an eye of your destination and eventually you will find your target. Assassinate Orchendor, gather his valuables and loot, and leave using the special Dwemer lift. When you return to Peryite he will reward you with the Spellbreaker.

Bugs

 * After you give all the acquired items to Kesh, you can pick his pocket and get all the items back before he created the fumes. This doesn't interrupt the quest because he is still able to create the fumes (even without those ingredients), and the Dragonborn is still able to proceed with the quest.
 * The room before encounter with Bthardamz may have a bugged floor, in which the player falls to the door leading into the lower parts of the dungeon. Try using whirlwind shout to get to the other side.
 * With the above bug with the missing floor, any follower will fall through and be lost.
 * If the player talks to Kesh while he is creating the fumes, the quest will not be updated.This may cause the trophy/achievement "Oblivion Walker" unobtainable,since the player cannot obtain Spellbeaker.
 * Update: You can fix this by killing Kesh, taking the ingredients, and activating the cauldron yourself
 * The Spellbreaker is a shield and is most often added without the echo-text telling you it has been added to your inventory, even though it is. Check your inventory properly.
 * If you give the required items to Kesh while he is at the alchemy table, the quest sometimes does not update. Note, the cooking pot may also trigger this as I have given him the items and he walked to the cauldron but nothing occurred. I had to load a previous save and return to get him to work properly.
 * After gathering all items and the quest says to give them, you don't have the choice of giving them to Kesh. (Killing Kesh should do the trick)
 * If you collect all items and do not have them in your inventory when you give to Kesh you cant processed with the rest of the quest.

Trivia

 * After completing this quest, Afflicted Remnants may be found wandering Skyrim.