Back when Soulless executed the slash against Kieran with the creepy pressure, the control he exhibited over his movements and how finely he condensed the attack revealed his current standard.
His improvements was one of the reasons why he was curious to know how Khaos fared against him.
Before Zenith Online's launch, where Umbra and Advent were of similar popularity, Soulless and Khaos were more or less of similar skill, with Khaos emerging slightly superior.
However, when the game began losing its popularity, Soulless removed himself from the environment and engaged in nothing but intense training to capitalize on his immense talent.
Because of this, his body had reached a state where he could withstand the frequent consumption of X-060.
Or, X-hancers of a 60% concentration.
After landing his strike against Kieran, Soulless' view of Kieran changed subtly.