Snow Follower's swing of his katana was enough to seriously wound Nessa, so... when his katana shook from the overabundance of energy, his thrust was definitely powerful enough to permanently extinguish the fire of life in Nessa's eyes.
The last series of attacks raining down on Nessa did more damage than she had realized. Her body no longer obeyed her, she needed time to recover, but Snow Follower acted quickly. He was really in a hurry to end this fight as powerfully as possible as soon as he could.
Thus, if no one interfered with their fight, Snow Follower would easily kill Nessa.
Well, that was why Adam used the power of lightning, cutting through the protective barrier with his needle and quickly rushing towards Nessa and Snow Follower.
'No... Am I actually going to die? Right now...?' Nessa inwardly muttered looking at the snow-white blade that seemed to be cutting through space approaching her.