To a certain extent, at least in my experience, NightWalkers are essentially demigods; while not immortal, they are DAMN close to being such.
Unless you had a means of zapping the thing to a crisp with Lightning or Light Elemental Attacks, you could go on smacking the thing all day long without ever killing the damn monsters; that leaves really only two ways to deal with them, both of which I have ample experience with doing.
The first is to overpower them by a large margin, stacking up damage to a point where the monster isn't able to recover any longer. This was the case when I fought NightWalkers with a significant gap in our Ranks.
Like Say me, who was a Gamma Ranker at the time, Facing Alpha-Ranked NightWalkers, in that case, I was generally able to beat them either into submission or to such an extent that their defenses weren't nearly enough to stop the onslaught.
