I was wondering what everyone thought of using these as a ideas for the great freeze:
First some base line facts/assumptions:
1) The senshi were not able to stop/reverse/or be present for the great freeze
2) Humanity survived by cryo preserving themselves (Senshi doing it or by way of tech)
3) We need the senshi in a position afterwards to lead the survivors in the rebuild
4) To have some people dislike the current world. These can be people from the old world who were not happy with the direction of the new world, or new people who came about and held regular riots forcing their banishment forming the Dark Moon.
To answer the first assumption the power that causes the great freeze needs to be a "cloudy concept" something that the senshi cannot simply point and shoot or possibly reason with. Thus it needs to either be so powerful that it makes Chaos look weak, something weakens the senshi first, or something natural and natural in a way that anything that they do directly to stop it will simply be either ineffective, or more disasterous. Such as an event that they need to "move" the earth, this would probably cause untold disasters everywhere and likely erase Japan from the map. As an alternative and an easier one to accept I propose "unfinished business" of a more diplomatic nature. After Galaxia's defeat and the general restore of the universe someone has to step up and clean up the mess. This could take years, decades, or centuries, depending on how bad it is. iirc it was stated that Earth was the only planet with life still on it left. The Senshi could have left to see to these worlds and ensure that life was comming back and leaving a small task force to watch home.
The Second is easy enough of a problem to solve ironically as it shows that if a select group were to be cryo frozen that a) They saw the disaster coming, b) had time to prepare to survive it, but c) could not stop it.
Third problem is harder as the senshi while known as "local legends" would be widely unknowns. They would have to work hard to raise themselves to any position of power, but remember Usagi was ELECTED. So unless she mass brainwashed everyone which is possible but highly unlikely (unless the Dark moon was right in some way). They were instrumental in the rebuild.
And finally problem with the Dark Moon. We are not told very much about them and where they came from, just that they were banished originally for being unstable, and possibly that the group that attacked later were their decedents. This says to me that they were disruptive enough that they were wanted gone, but had not done anything warranting death outright, possibly through a pardon on Usagi's part. They must have had a generational ship. furthering the idea that Crystal Tokyo was established and stable at this time. So it was not likely people who were from the old world and unhappy with the new one. All this is only important to bring up one important point. The fact that the roots of this problem post date Crystal Tokyo show that the people who were cryo tubed had been screened to prevent just this from happening, hence adding more time to the "see problem, we need to freeze people, how long and how many can we succeed with issue"
Possibility #1 Most of the Senshi were off world at the time, and return to an ice ball. There were survivors who made it to safety, but the basic idea was someone who would have otherwise been a minor threat to the senshi got in a low shot when they weren't looking, and the clean up can either be done instantly with so much damage to the planet that they may as well say forget it, or wait it out and prepare those that survived for the later rebuild.
Possibility #2 "It was (him) -problem-" something that they couldn't fight directly. How exactly would they in modern times stop a world wide effort to stop global warming. especially if this effort is what leads to the great ice through accident, people realize the mistake and know that with this boo boo (Lets stop global warming by nuking volcanoes) they only have 10 years before a self caused eco melt down. so they draw lots pick needed people and freeze them.
Possibility #3 The great freeze only refers to the cryo freezing and not the world as a whole, say a nuclear war occurs that does major eco damage, reaction from the world is same as in situation #2
So here are my theories which are summed up as magic vs Human stupidity... unfortunately I think the one closest to the truth is stupidity as any magical problems are easily magiced away.