|Slivers||Leras, Rashek, Kelsier, Vin|
|Status||Whole, conjoined with Ruin|
Preservation is a Shard of Adonalsium. Its original Vessel was Leras, but has since been held by Kelsier, Vin, and Sazed, who also took Ruin and "intermingled" the two powers, forming the shard Harmony. In the Terris religions Preservation was known as Terr as this meant "to preserve" in the ancient Terris language. Preservation is known as Herr to the Southern Scadrians.
Preservation seeks to provide stability. It seeks to preserve the world and its inhabitants. According to Ati, if Preservation had complete dominance over a planet, he would make everyone and everything remain frozen out of fear that they would get hurt.
Preservation fuels Allomancy, one of the three Metalic Arts on Scadrial. Each human has a bit of Preservation that gives Allomantic power and free will.  The solid form of Preservation's power, a metal known as lerasium, grants the powers of a Mistborn to those who ingest it. When burned by a Mistborn or Misting, it drastically increases their powers.
The deal and betrayal
Preservation and Ruin, the two Shards on Scadrial, struck a deal to create sentient life on the planet. Preservation would have a sliver more of itself in humans, but Ruin would be allowed to destroy the world.
Preservation broke the terms of the agreement by sacrificing his mind to create a prison for Ruin's mind, preventing him from destroying the world. Furthermore, in an attempt to balance the power (since some of Preservation was now stored in humanity), he sequestered away a portion of Ruin's power in the metal atium. The Well of Ascension, Preservation's liquid essence, was created to contain Ruin. After sacrificing his mind to trap Ruin, Preservation manifested itself as the mist spirit whenever it wished to influence events directly.
The mists of Scadrial were left behind by Preservation to awaken Allomancy in the inhabitants of Scadrial, albeit in a violent way. The mists were encouraged by Ruin to choke off sunlight to the land, and were named the Deepness since they prevented food from growing. They also provided power to enhance Allomancy by Vin, hundreds of years later.
The Lord Ruler and the Collapse
When Alendi travelled to the Well of Ascension, Preservation attempted to stop him, and in attempting to do so, murdered one of Alendi's travelling companions. Afterward, Rashek took up the power in the Well to prevent the release of Ruin, and used it to reshape the world of Scadrial in an attempt to get rid of the mists. He was not very delicate with the power, starting with moving the world too close to the sun and having to make constant adjustments to compensate. Preservation's intent can be seen here, as he could not destroy, only change.
Preservation once again attempts to stop someone from giving up the power at the Well when Vin arrives there after the Well had been refilled. Prior to this, Preservation appeared to Vin on multiple occasions during the Siege of Luthadel and to Sazed as he and Tindwyl were studying Kwaan's inscription, found in the Conventical of Seran, where it tore out a specific section of the text to try to give them a clue about the power at the Well. Vin releases the power of the Well, thinking it is the right thing to do, thereby allowing Ruin to escape. It immediately goes on a rampage to destroy Scadrial. Preservation wounds Elend in an attempt to get Vin to use the power, but when this fails, it shows her the last remaining lerasium bead in order to save Elend's life.
During the Siege of Fadrex, Preservation appears one final time to Elend after seeing him almost ready to give up when escorting a large group of captured koloss back to Fadrex. By this time, Preservation is too weak to perform any significant actions and can only vaguely communicate with Elend, and shortly afterward, the remnants of its mind are destroyed by Ruin, and Leras falls out of the mists and into the ash as he dies.
In the days of the Breaking, Preservation sends the mists during the day to touch all of humanity, in a countermove to Ruin being freed from the Well and utilizing the Inquisitors and koloss to destroy. With the kandra guarding the Trust of atium and the Pits of Hathsin destroyed, there are no other atium caches for Inquisitors or Mistborn to gain control of. Preservation makes the mistsickness affect a sixteenth of Elend's army; sixteen metals, of which atium was one. Just prior to the last battle between the human and koloss armies, Elend and his army reach the kandra Homeland, and Ruin's body: the atium stash. Elend realizes that the one sixteenth of his army that are Mistfallen are all atium Mistings. Preservation planned for the hundreds of new atium Mistings to burn the atium, thus denying Ruin from gaining access to its own power.
The death of Ati
After Leras dies, the Shard is taken up by Kelsier for a very short time, by using an artifact stolen from the Ire. He gives up the power to Vin following her battle with Marsh. The reasons why Vin is able to take the power remain shrouded in mystery (even to Sazed after he takes up the Shard). When Marsh kills Elend, Vin realizes she has nothing more to live for and assaults Ruin directly, killing both Ati and herself in the process.
The end of Ruin was Preservation's plan all along. He needed someone new, and therefore not molded to Preservation's intent, to make the sacrifice needed to destroy Ruin. Leras spent too much time holding the Preservation, and was thus unable to act against its intent.
Sazed takes up both Preservation and Ruin following Vin's sacrifice, and becomes the Vessel of both Shards following these events. He uses the power contained by both Shards to reshape the world and fix the damage incurred by Rashek during his time with the power, and Ruin's final attempt to destroy Scadrial.
- No Splinters still at the time of Aol
— Theoryland - Oct 5th, 2013
- Would Sazed drop Ruin and Preservation or Harmony?
— Reddit - 2013-04-18
- The Hero of Ages chapter 75
- The Bands of Mourning chapter 22
- Annotation for The Hero of Ages chapter 70
- Allomancy table poster
— Brandon's website - 2008-12-12
- The Hero of Ages chapter 46 epigraph
- The Hero of Ages chapter 4 epigraph
- The Hero of Ages chapter 56 epigraph
- The Hero of Ages chapter 82
| Mistborn Era 1|
The Final Empire · The Well of Ascension · The Hero of Ages
|Characters||Vin · Kelsier · Sazed · Elend Venture · Marsh · Spook · Breeze · Ham · Clubs · Dockson · Straff Venture · Zane · Ashweather Cett · Tindwyl · Allrianne Cett · TenSoon · Yomen · Quellion · The Lord Ruler · Alendi · Kwaan|
|Places||Final Empire · The Dominances · Luthadel · Kredik Shaw · Pits of Hathsin · Kandra Homeland · Urteau · Fadrex City · Tathingdwen|
|Ethnicities and Species||Skaa · Nobles · Terrismen · Inquisitors · Koloss · Kandra · Mistwraiths · Southern Scadrians|
|Organizations||Skaa rebellion · Steel Ministry · Keepers (the Synod) · Worldbringers · Noble Houses|
|Mythology||The Deepness · Terris Prophecies · Well of Ascension · Hero of Ages|
|Era 1 books||Mistborn: The Final Empire · The Well of Ascension · The Hero of Ages · (Mistborn: Secret History · The Eleventh Metal)|
|Era 2 books||The Alloy of Law · Shadows of Self · The Bands of Mourning · The Lost Metal · (Allomancer Jak and the Pits of Eltania)|
|Shards||Preservation · Ruin · Harmony|
|History||Classical Scadrial · Final Empire · Catacendre · Elendel · Southern Scadrian|
|Magic||Metallic Arts (Allomancy, Feruchemy, Hemalurgy) · Metalborn · Mistborn · Misting · Savant · Ferring · Twinborn · Compounding · Atium · Lerasium|
|Other Media||Mistborn Adventure Game · Mistborn: Birthright · Mistborn film · Mistborn: House War|
|Shards||Ambition · Autonomy · Cultivation · Devotion · Dominion · Endowment · Honor · Odium · Preservation · Ruin · Survival Shard|
|Planets||Ashyn · Braize · First of the Sun · Nalthis · Roshar · Scadrial · Sel · Taldain · Threnody · Vax · Yolen|
|Terms||Adonalsium · Sliver · Splinter · Realmatic Theory · Intent · Focus · Investiture · Shardpool · Spiritweb|
|Other||Hoid · Seventeenth Shard · Shattering · Worldhopping · Letters · Silverlight|