NSX Amaterasu needs a bit more damage. Many times when I attack someone with it, they just run away and I am left chasing them, using its ranged attack which still doesn't kill them in time before I die to their teammates.

It is okay in extremely small fights or isolated areas as you will have the upper hand anyway if you can surprise the enemy, but is not viable if the enemy has team support because it takes so long to kill.

I think 2 slashes plus one ranged attack should be enough to kill, and this wouldn't be oppressive or make other knives obsolete. Another option would be to increase slashing rate. Or maybe even some other change like increased running speed when wielding, ability to use the ranged attack at the same time as running, or the ranged attack does much more damage but requires charges gained through melee kills.