Empty Attacks:: 自分 transcends 相手's framework of attack
Annihilation:: 相手's very existence is erased by 自分
Sword Dance:: 自分 dances an empty sword dance
Ineffable Mind:: 自分 transcends all model of experience
Imperceptible:: 相手's own death is uncertain to 相手
[Sword of Emptiness]:
"Sometimes, someone’s existence was felt more strongly not because they were near but because they were not." Thus, the absence of a sword in 自分's hand was felt more strongly than any weapon—自分 had effectively wielded emptiness as a sword, cutting 相手 w/ a paradoxical nothingness, rendering 相手's defences utterly futile as 自分 guarantees 相手's immutable destruction.