Splinter

A Splinter is a specific kind of fragment of a Shard's power. A few of the Shards of which readers know have been Splintered. Splintering is when a Shard is broken into dozens or hundreds of small pieces, so that no one can take up the Shard's power. Odium has Splintered three shards: Honor, Devotion, and Dominion. Spren, seons and skaze are all Splinters. Most of the Shards have already, of their own volition, Splintered themselves to either create life or set up each their respective magic systems. They can do this and not die. For example, while Rayse is still alive and holds Odium, Odium is slightly Splintered. However, Splintering a Shard is not permanent.

Brandon has stated that a Splinter is a piece of a Shard that is fully autonomous, where an avatar is not. So, something that is Splintered does not consider itself - and would not be considered by the definitions  - an actual piece of the Shard, and has free will. So once it has free will, and/or could develop free will (because some of the Splinters haven't gotten there yet), but is fully cut off from the direct control and self-identity of the Shard, then it is called a Splinter.

Brandon has also stated that a Splinter is the qualitative opposite of a Sliver. Whereas Slivers are people who have been influenced by Shardic power, Splinters have never been human. One distinguishing factor of a Splinter is that it often has an intent, separate from that of its Shard (i.e., spren which attained sentience before Shardic influence). Splinters are a blend of more of the Spiritual and Cognitive Realms and less of the Physical Realm.

“	A Splinter is a term used by certain people in the cosmere for power of Adonalsium which has no person caring for it, no ... no person holding it, which has attained self-awareness.	”
–Brandon Sanderson

Characteristics

It isn't yet fully known just how Splinters are created, but a Shard must be actively involved, whether by intent or by default. Since Odium killed Tanavast, who was the Shardholder of Honor, Honor was splintered by default.

It's very hard for most Splinters to leave the realm where they were Splintered.

Known Splinters

- The spren on Roshar before Honor and Cultivation arrived.

- Some Honorspren, (such as the Stormfather), are Splinters.

- Since Devotion on Sel was also Splintered by Odium, the Aons inside Seons are Splinters too.

- Endowment on Nalthis was splintered as well, so the Divine Breath held by the Returned are also Splinters.

Theory

Given the former existence of Adonalsium and of the Shattering, the fractured Shards left later developed a drive or fundamental nature to themselves. Shards are immense in scope and power. This power yields abilities that seem only limited to the imagination. In fact, readers know from the Words of Founding that Shards have created life from their power.

However, concerning spren with regard to Splinters, spren seem to thrive on ideas and concepts of the human mind. By observing and often mimicking what they interact with, spren reveal that they have a core nature. They are drawn to some kind of theme or purpose. This tendency, to have and to hold true to an idea or states of environment treflects what they themselves are. In this way they are reminiscent of matured Shards. Shards seem to have a compulsion to see out a particular ideal, usually summarized by the name they adopt. The spren seem to mimic this type of behavior and single-mindedness.

Based on such observations, it can be postulated that spren are little pockets of Shardic power. Unlike raw Investiture, which is simply harness-able energy, spren are power with a measured intelligence and will. They are like Splinters of a soul. It is easier to understand this position when one visits the Cognitive Realm. There the spren seem far more complex, and even potentially dangerous. (There are whispers of larger spren that have intelligence and memories who live there.)

Splinters are entities of power that were never alive as humanoid, but attain a level of ... consciousness. This is where things remain a bit fuzzy. It cannot be denied that spren are intelligent, at least in a broad sense. By contrast, the Returned on Nalthis also carry with them a Splinter in the form of a Divine Breath. In fact, every Breath might be considered to be a Splinter since each is a portion of the power of a Shard but a Divine Breath is unique. Yet it must be asked, are the Returned each a person brought back from death by infusing each their souls with a Splinter, or does the Splinter itself inherit the body of a dead person? The answer to this might simply be both, and for this particular argument the distinction is not important. What matters is that there is an intent behind both a spren and Divine Breath.

Further, it might also be guessed that Seons could be considered Splinters. They are far more than just a symbol of Aon-dor, and they exemplify obedient intelligence with a profound memory and distinct personality. In this way they might be the most advanced form of documented Splinter - in Cosmere - to date. However, there is a potential in the spren, and if the Nightwatcher and Stormfather can be confirmed as massive spren, they might be the most powerful Splinters known to humankind. There are more than rumors that the Nightwatcher can grant requests that come with an associated boon. If this is more than a myth, the implications are might well be staggering.

With regard to Scadrial and the existence of Splinters, according to the historical records of the kandra, these shapeshifters are intelligent beings that once were mindless creatures. They gained their intelligence via the powers of two hemalurgic spikes. Hence, the connection between spikes and Splinters. This may be an unrelated correlation, but the similarities are strong, and only separated by scope. Most hemalurgic spikes are simply a form of spiritual surgery, ripping one soul apart and splicing pieces of that soul into another person. But with the kandra, they grant actual consciousness as if they were a Splinter themselves. Perhaps they are.

So, just what about the whispers of the Voidbringers. On Roshar, there are tales of monsters built of stone and darkness that once sought the destruction of all sentient life on that world. The rumors are whispers at best, but there remain several well informed connections. Voidspren are now actually real, humans are dealing with Splinters that are openly hostile! Likely, these spren move with an intent and were created purposefully by a destructive Shard (i.e., Odium). There is a great destruction coming!

There are evil spren sent to do the work of a destructive Shard! Readers, be sure to look for the patterns! These Splinters seem to be mimics or replicas of what already exists on Roshar, which goes against all that has been observed on other worlds where the Shards manifest uniquely when exerting their respective powers of Investiture. If this "Dark One" seeks to mimic his fellows, then his touch may be subtle. Look for the signs of madness or corruption of what already exists. Red eyes ... perhaps this is another sign to watch for. (There are reports that the people who wage war on Roshar have recently been seen with glowing red eyes.) This might be the only reliable way to recognize the servants of this being. Then again, it is possible that there are multiple Shards attempting to cause upheaval and destruction.

With regard to the Voidbringers, there are more reports coming in all the time ... so to speak. While there might well be a great bell just beginning to toll the final hours of this place, the air almost hums with tension and someday this world might break. Hopefully, the messengers can find redmption amidst what is to come. Does this seem all too familiar? Yet another world must not die!

- Paraphrased from transcript.[1]