Well done, soul chains and golden lance, but this was a thick hide accustomed to the weapons of the gods. Even now in death as its husk withers and writhes, dragged out of the river in chains like an enslaved captive, the beast had tricks which made it the guardian of this layer, to prevent mere mortals from somehow breaking the seals and entering in. Or perhaps more so to prevent the souls from escaping their proper place. Even in death did its mere presence serve as a tether and keep these souls bound, although a few did escape due to its death. Often it was from this realm did the dead find their way back into the world of the living. Reborn anew in an incarnation, just as the serpent slumbers biting its own tail. 

the beast hissed, or rather the souls which infested its remains did, as lance pierced the rotten brain and iron hide, as chains tore into scales. Did they forget that it was not the snake itself which controlled it, but rather the spirits inside, the strings which controlled the puppet. Thus perhaps destroying or damaging the puppet would limit their ability, yet this tactic would be for naught. This great hell serpent was no hydra, but certainly just as tricky to face. Behold now, great warriors as the spirits pulled the snake back, wriggling from the chains and pulling the one on the other end back as the pull of the thousands of angry souls fought this tug of war with the collectors hundred. Even now, wounded and bleeding a foul ichor of semi-congealed blood from the new wound upon its head, smelling of ammonia and rotten sulfur, the snake resisted. Its scales peeling off, molting, shed anew, and all damage done seemed to disappear, slipping off the old husk's husk as the remains were cast off. 

More so, however was the new sheen of its hide, no longer riddled by the weapons, but certainly looking as if the snake was indeed still alive. It was not the regeneration which made this foe so great, but rather what happens as it shed its skin. Try again, Collector or Cavalier your weapons will be turned away, your lance shall not pierce its scaly hide twice, nor shall your chains dig into its flesh. This was the hide which evolved, ever increasing its potency against whatever dared to injure it before. Try it once more, and you shall find your weapons fail you, as none shall prevail as they found. The old skin defeating countless of ordinary blades and more, this one that it wore now shall defy even the lance of nigh a god. Which is to say the old serpent hide would be indeed, quite a treasured relic should anyone be crafty enough to find a method to fashion it into armor. Yet how shall one cut such thing?

"Foolsssss! You ssssshall not sssslice ussss, our new sssssskin sssshall sssstop you..." The spirits hissed, driving their centuries old rage within the beast, it shall not be.

Yet, there was one amongst them who smiled, as he hopped off the longboat, the hunter who marks his quarry well. Dress in the wraps of furs and wool, his weapons place well upon his back. A totem hung from up a belt loop and other strange spiritual fetishes of wood, stone, or animal parts. A bow drawn back, a whispered prayer for a bountiful hunt. An arrow unleashed, the fingers let fly, the wrath of the hunter as the howling wolf came to life. Imbued with the spirit of the hunt, a slaying arrow empowered to kill the prey, to pierce the hide of this monstrous beast miraculously as it hissed again, the arrow penetrating the hide, not deep but still an irritant to anger the spirits further into motion as they rear the serpent's head to strike at them once more, lunging at Eclipse, and the others left on the boat.

But it was already dead. Wasn't it? There was no giant snake, here, physical damage to the puppet was fine, but they had all missed to sever the strings that made it dance. Come now adventurers, surely there must be enough brains amongst you to make a brain salad. The great guardian died certainly, but how it was killed is the mystery. With an nigh impenetrable hide, though it was no mystical lion perhaps it was crushed or suffocated to death? And yet clearly it was cut into pieces, with some blade no less, a blade which must have been beyond godly to bypass its defense.

Or perhaps the warrior was simply clever, knowing just where to strike. A weakness so obvious, and yet it lies at the heart of the issue. To kill what was already dead, something similar should be done, else perhaps the puppet shall continue to dance its maddening dance. Its forked tongue flicking out of its gaping maw, jaw broken but still held by the force of will, the unbroken broken spirits holding the corpse together in this act of punitive vengeance against the champions of the gods.

"Die and Join ussssss!"