In those days, when Charles the Conqueror stepped into the Undead Plane, he encountered a Demigod Lich. The battle between the two almost destroyed the Undead Plane, even after many years, Charles the Conqueror's fame spread through countless planes. That particular battle still remained fresh in his memories and he even admitted that it was one of the most challenging fights he had gone through.
And that Demigod Lich had been using a Life Affixing Rune.
It was also because of that battle that the Life Affixing Rune was revealed in Noscent. Countless mages started researching this Life Affixing Rune.
People gradually discovered that although the Life Affixing Rune had all kinds of shortcomings, its stealthy nature was enough to make up for it. Being hidden meant safety and for Liches whose existence depended on their phylacteries, safety was the most important. They would be able to endure all kinds of shortcomings as long as it could be a little more hidden.