Noah's three Exclusive Skills didn't seem so special at first glance.
[Phase], [Shadow Magic], and [Projection].
With the exception of some moves that could be done with [Shadow Magic], they were mostly useful for defense and evasion.
However, after honing his abilities and properly practicing with these Skills, Noah could properly use them for offensive moves.
When he started his fight with Britta, he used his [Shadow Magic] to defend himself, while using [Phase] and a bit of propulsion to slip through the ground and appear behind her.
Then, he used his voice to call her attention to him. This, along with the effects of her [Greater Full Sense], allowed her to locate his position, even though she never saw him leave his black cocoon.
Even if she suspended disbelief for that moment, due to the directive of her senses, Britta encountered another dilemma when there was no visual representation of what she was sensing.