Stigma

Stigma (スティグマ, Sutigma) refers to the physical mark left on the body of a human as an after-effect of performing an Adolla Link.

Overview
When a human who doesn't possess the Adolla Burst performs an Adolla Link, the experience leaves lasting physical damage and can be extremely different from individual to individual. People who possess Stigma are essentially marked as those who bore witness to Adolla, and bearers of the Adolla Burst can easily perform Adolla Links with Stigma-bearers, as Shinra Kusakabe was able to sense Konro Sagamiya's plea for help across Asakusa through one such link.

In recent times, the White-Clad have taken steps to eliminate those who bear a Stigma, as their knowledge about Adolla is a potential threat to their plan of bringing about a Second Cataclysm.