As the name of the technique implied, Intangible Step was a skill of the Bladed Ghostmancer Class that could turn Soulless' body intangible for a split second. During the brief window, Soulless grew invulnerable to all physical attacks.
Under normal circumstances, Soulless wouldn't use this ability, but Kieran's attacks were all guaranteed one-hit kills unless stated otherwise. This was evident by the sense of danger they produced.
After avoiding the Seethe Burst, Soulless' body returned to its proper state a fraction of a second later. Because he had avoided suffering damage, a hint of increased pride seeped into his gaze.
As he looked at Kieran while showing a subtle smug smirk, Soulless spoke lightly. "Given that you can use Techniques freely, or rather that you're the godfather of using Techniques, you should know what mental power is."