Infon

Infons (情報子) or Information Particles are the smallest particles and the building blocks of all things including Souls and even Skills. Their mass is as close to zero as it gets. They are unaffected by space and time and are thus able to move in any situation and transfer information with zero time difference.

Observing them is extremely difficult and normally only possible under certain conditions, like inside Rimuru's stomach or an Infinity Prison. The ability to alter, combine, and abolish skills are an example of limited manipulation of Infons. Directly interacting with them is only possible as Digital Natures and a requirement to move in the Stopped World.