The moment Night Eye died, Souta waved his hand and canceled all the active skills around him. Blood, webs, and shadows were dispersed on the ground. Even if Night Eye tried to escape, Souta would still capture him. In [Traceless World], Night Eye couldn't hope to escape unless he killed Souta.
Killing Souta was already difficult to imagine so when his hand got sliced his hope of leaving this place alive became nonexistent. He couldn't even wield his bow properly with one hand and even if he resort to close combat he wouldn't be able to best Souta. Although Night Eye was good at close combat, it wasn't comparable to experts like Souta who mainly fight in that range.
Souta sat down on the ground and leaned his back on a boulder. He was quite tired. Fighting someone at Four Shackles Realm was too much for him. He was lucky that he had a bunch of high grade artifacts with him or else... He would be forced to use that.