|[[File:Shadow Star.png;Shadow Star being used on Mifune.|250px]]|
|Manga Chapter Debut||
|Anime Episode Debut||
Using Soul Resonance while Tsubaki is in the required mode, Tsubaki is able to manipulate and possess Black Star's shadow, in order to form it into a whip-like entity. This is subsequently used to repeatedly attack the enemy, with the intention of landing multiple crushing blows, that are also capable of slicing the opponent apart. However, through examination, the usage of this form of Shadow Star has the side effect of slowly killing Black Star, due to the nature of the form Tsubaki must assume.
After confronting the spirit, originating from the Uncanny Sword and currently residing within Tsubaki, and accepting the consequences that Black Star may face on his chosen path, he and Tsubaki are subsequently able to unlock the true resonance derived from this ability.
- Although Chapter 16 is refered to as this ability's debut, the name of the attack was actually stated much earlier in Chapter 10 but as Black Star couldn't even maintain the Uncanny Sword mode for a total of 10 seconds, the technique ultimately failed, miserably.