The two squads worked in tandem with Brenden and Dad to control the movements of the NightWalker as my strategy began to show what I was looking for.
Injuries.
By this point, I was no stranger to the odd regenerative abilities of this particular NightWalker, and once the fire died out, I saw black smoke billowing off the monster, not from being charred; no, this was its form of blood, and by the copious amounts of gas spilling out of its body, especially from the large hole from where I had stabbed it, I was able to estimate its heal timer.
Just like when fighting Giants or Trolls, who are known for excessively high regeneration, there were only two ways to deal with such a thing: stack the damage to a point where it can no longer keep up with healing the injuries, or blast it away with a single, extremely powerful attack, and in reality, I was planning on doing both.