The People are the ones who died in order to become Fayth. About that tornado thing, I have no idea what you mean…
Yeah, they’re Zanarkands survivors of the machina war who have become the fayth for the summoning of Dream Zanarkand.
As for the tornado thingy, i believe it appears that its coming off the fayth, and so it maybe a physical manifestation of the collective power of the fayth which Yu Yevon uses for he previously mentioned summoning. At the end of the game, you also see that it dissolves into the souls of the fayth or the summoned people, so it might also be a physical manifestation of not just the magic power of the fayth, but also the container of the souls being created in the dream Zanarkand. This is just my theory though…
The water, in my opinion anyway, is not actually water, but some other solution (possibly the same thing that pyreflies are mode out of) that is being called by fayth across Spira to "summon" (to use the game’s words) the dream Zanarkand.
As for the tornado thingy, i believe it appears that its coming off the fayth, and so it maybe a physical manifestation of the collective power of the fayth which Yu Yevon uses for he previously mentioned summoning. At the end of the game, you also see that it dissolves into the souls of the fayth or the summoned people, so it might also be a physical manifestation of not just the magic power of the fayth, but also the container of the souls being created in the dream Zanarkand. This is just my theory though…
As i said. its just my theory, but ive never seen anything to contradict this and may also explain why the citizens of dream Zanarkand can go to the Farplane which is another issue ive seen come up at times
It never explains that in the game that I know of