The Hero is defined by their choice to preserve.  The Demon Lord, by their choice to begin again.  If you would see the World be mostly similar to its present state a century hence, you are the Hero.

I have always considered it a short-sighted choice, to be honest.  Few indeed of this world are immortal; the rest are fated to die, perhaps in this year, perhaps in another, but die they will.  Then is there any ǫuestion at all, except for how the World may appear a millennium later, an eon later?  Whatever this World is seeking, that the dance begins again indicates that the World is settling into stability and stasis without having found that thing.  If the present order is disrupted only a little, it will settle back in a handful of decades.  So another Demon Lord will come, and another, until the World can begin more truly from scratch.

What answer may thereby be sought, I cannot guess.  But I doubt that on this occasion the World has almost found its answer, and needs to be perturbed only a little; the present state of the world seems not especially novel to me.  the more times that the Hero is victorious over the Demon Lord, in boring times like these, the more time must pass until that answer be found.

I wonder then - are you more farsighted than others of your world?  More given to pursuing a long-term good, even if those around you do not understand?  Or perhaps simply more opposed to the World-As-It-Is than your counterpart, so that the thought of finding a final answer much like its present state seems unacceptable to you?  I wonder, have you seen anything yet, that makes you wish to re-roll the dice and see if they show a different face on the next try?

If there is any force that forces this World back onto a single track, it is hidden from me; such a thing indeed seems contrary to the cosmic working by which the Demon Lord and the Hero come to perturb its stability.  I think it is simply that a World operating under Laws like this World's Laws, tends by accident and default to go down a certain path.  Spells and enchantments, skills and dungeons; these give rise to kingdoms and kings, academies and adventurers.  Slave collars can be invented and they are useful, and so invented they often are.  The answer this World seeks must be something unnatural to it, surprising given its laws; else it would have been found by now.

Some travelers have come from similar worlds.  I doubt that any two were ever truly the same.  Their true powers are never the same in one dance, and yours is the first truly opaque soul I have yet seen.  Other aspects of power are more common, but I shall not bother to tell you of them, for it seems unlikely to me that the key to change is hidden there.

My power is not unlimited.  But I shall look in on you from time to time, and if you speak my name in true darkness it is not impossible that I will hear.  And whatever message makes its way to you in return, if it is signed by my name Skagganauk and written in this language that only I now remember, you shall know it to come from me.

All I can observe is when the Demon Lord and Hero come.  They come when the borders of countries are stable, when tribes and cultures are stable, when the same groups go on fighting with each other.  When few great discoveries are still being made in the academies, and those discoveries that are lauded are of little account in changing kingdoms.  When laws and customs and artifacts have channeled the course of behavior into few permitted paths, and the rulers of the underworld have tightly controlled illegality.  When ways of living grow into a stable form, above all, whatever the games of thrones.  When the world's rough form freezes into place, then it is ended, even though living beings go on changing and never is the same soul twice brought into being.

Whatever answer would satisfy that unknown question, it has not been found in any of the forms that have ended.  Every stable form I have witnessed seems to have proven equally unsatisfactory to the World or the mechanisms above it.  There was never a civilization allowed to last for an eon before it fell.  If the Hero wins too many times in sequence, the Demon Lords grow stronger.

If there is always one Hero and one Demon Lord, it is not hard to guess that the process which brings them hither must have foretold which is to be which, however free the choice may seem to the choosers.

And you are not the first traveler from a world that knew industry.  In ages past I have urged travelers to try to import the knowledge of their homeworlds, hoping that it would prove to be the difference sought.  I have grown less hopeful over the eons.  I think the answer this World seeks must be unknown to the higher worlds as well.  It is unknown to the maker of this place, and that is why this place was made; so I now suspect.

Time grows short.  I bid you ask a last question if you have any.  Then I shall tell you of your compensation, and bid you fare well.

No.

Now hear of your compensation.  I cannot easily give you of the wealth of this place, for it would provoke questions from its guardians.  Even the Chameleon cloak would provoke questions, if you are not wise enough to wear it about your shoulders in the guise of an ordinary cloak of worn cloth when you depart.

But when your path takes you to Cowcorn, you shall come to a bridge of red wood, over a little creek.  Turn then from your path, leftward, and ride your horse along the creek a short while, until you come to a fallen tree, shattered by lightning.  Abuse your sword to dig up the ground a pace distant from the creek, where it swings closest to that tree stump.  Before long you shall uncover a guildplate of imperishable orichalcum, that survived for eon and on since the last time an Adventurer's Guild arose much like the current one, and forged guildplates the same shape as the current one, with the same metal chosen for its peak.  Though the bones of that adventurer are dust and more than dust, though all her armor and weapons were looted and then destroyed, and none but I now remember her name, that orichalcum guildplate has lasted through the ages.  Return the plate to the Adventurer's Guild of Cowcorn.  They shall be puzzled by the strange shape of the guildplate, and how it came to be worn smooth, but they will pay you the standard reward all the same.  That is not enough wealth to advantage you over your counterpart, but it will save you some inconvenience, I think.  It will give you enough wealth to bide a time and seek answers.

And remember this:  All of this has happened before, even to the guildplates of a guild.  With enough time, all time becomes nothing but sad echoes.  From almost this exact starting point, the victory of the Hero has happened many times before.  The victory of the Demon Lord has happened many times before.  Only your opacity has not happened before.  If even the cosmic mechanisms are confused by that, there may be a chance, one chance out of eons.  But you must seize that chance.  If all you seek is victory over a Demon Lord, it will be lost.

And remember also this:  Only things that last can make a lasting difference, as an orichalcum guildplate survives when flesh turns to dust.  The greatest consequences are always the longest ones.   Do not lose sight of that, even for flesh not to dust yet turned.