The Creationists, and a few primordials, used these tendrils of energy to create worlds across the multi-verse. The world was built around them and if one were to somehow find the beginning of the string, then they would find themselves in a Sea of Entropy.
- Gibberdand, grell instructor of the School of Entropy - "Chaos Theory of the Spheres"
The Decomposition String is so deep in the core of worlds that it is out of reach to most. In the Creation War, on the world Bal-Kriav, the future god Tarâk sought out this wonder. He had learned of its seemingly unlimited energy, needing it for a great device he was planning to build. In 7500 DE, from the lowest point of Surturs Artery, he used an army of elemental slaves to bore in the direction of Bal-Kriav's outer core. Three centuries later, Tarâk found what he was looking for. Nearing the Decomposition String, he and his guards were overwhelmed by entropic energy. His earth elemental miners were transformed into chaos archons. Tarâk suffered entropic mutation, leading to him becoming an abomination. It also changed his elite guards, the Slaad Hexos, into mockeries of their original forms. After years of experimentation, and the loss of thousands, Tarâk learned to use the Decomposition String for other purposes. At safer distances, and over months of exposure, he turned hundreds of his mortal minions into a new race called the Grimlock.
It is cheap and powerful, but a product of entropy. It may help you out in the short term, but remember tree-man that this is raw chaos and not energy that has been turned into something higher and more stable like the motes of life energy powering your staff.
Silvanus used the warp matter obtained from Tarâk to empower a network of treants with the spell Transport Via Plants. This spell works by joining all the treants of the Roots of Núlananya so that a druid using the aforementioned spell can go to any other known treant in the series - including ones on far flung worlds. The side effect of using warp matter led to the Núlananya Rift. This did not come about from a problem with the warp matter, but with the planting of the seed that would become the Núlananya tree. Unbenowst to Silvanus, or more likely from primordial misinformation, he buried it in the chaos infused grave of a long dead primordial.
The Decomposition String holds particles of concentrated elemental energy called warp matter. The World Splitter was powered by one large piece of this stuff. When the World Splitter crashed into Bal-Kriav, its warp matter engine sunk into the Underdark, creating a bore hole that descends all the way down to the Decomposition String where it was absorbed back to whence it came.