Now, I know that the Pankratosword is a technique that allows one to literally cut an atom, hence causing a nuclear explosion. This got me to thinking...how was this even learned? Let alone how was it taught? It is literally quite the mystery for me since I have been thinking on this and any usage of the technique would kill the user and everything around them.

So, how exactly did one learn this? How was it then taught to other blademasters? I know that they say the Pankratosword is what destroyed the Redguard homeland, but they never really confirm. They only say that this is the most likely scenario.

Any ideas? I have absolutely none.

While I don't know how was it originally learned, Redguards have these things called "Memory stones" which (basically) allow you to store memories and knowledge, allowing others to gain them by contact with the stone (this was how the stance needed to initiate the Pankratosword was learned by http://www.imperial-library.info/content/lord-vivecs-sword-meeting-cyrus-restless).

"To become an Ansei of the first rank, a sword-singer had to demonstrate an ability to form the Shehai, a sword formed out of the singer's own spirit."

I would assume once you have been taught to do this, the only limits as to what you can do with it are your strength of will and your imagination.

It's quite daunting when you realized the Hiradirge who were said to be responsible for Yokuda's destruction had their asses handed to them by another Yokudan faction possibly another band of Ansei.

By meditating in a state of deep sensory deprivation and contemplating the nature of the universe, one's non-visual senses can become enhanced to the point that you can hear the vibration of the atomos. The fabric of reality in TES is made up of tones, hence tonal architecture. Once one has developer the ability to sense the location of atoms the next step is to develop the precision of the shehai to the point that you can split one.

This is why Frandar Hunding had to retreat into a cave to write his Book of Circles (sensory deprivation.)

^Made up.

The Almighty Word can only be remembered. It isn't passed down or learned but recalled. Frandar's children are the bloodmemory of the Make-way Sword.

Knife-scholars at the University of Cut-Your-Way talked about the possibility of Pankratosword long before it was ever made reality. Several quite complex theories still survive, the most popular being Saal Lykri's Untrustworthy-Metacarpal-Spirit Model, proposing the existence of very small gods whose task it is to hold everything together. If the swordsman were to cut these gods, Lykri claimed, everything around him would collapse into dust. Lykri later set out to prove his assumption that gods can be cut, much to his personal detriment. They still have some slices of his skull in Sentinel's temple of Leki.

^Also made up.

Gigantic Yoku pantheon includes literally the stuff of matter as gods.

Pankratosword isn't nuclear detonation, it's deicide.