Another possibility is that Ta and Ko-Matoran's heat/cold resistance is caused by their sense of temperature being shifted slightly, so that what would be considered "normal" temperature by, say, a Le-Matoran would be considered cold or hot by Ta or Ko-Matoran, respectively (so Ta-Metru to a Ta-Matoran feels the same as Le-Metru to a Le-Matoran). In that case, it might be that Su-Matoran don't have resistance to heat, they just prefer feeling warm whereas Ta-Matoran prefer feeling normal temperature. I can ask Greg about it if you want.
I'd be interested in an answer to this, though you might wanna try to phrase it more concisely for Greg.
To be clear, I would lean toward the latter. If they have any actual heat resistance I hope it's lesser than Ta, as impractical as that sounds, if only because that would make it weird that Ta would have really nothing unique. Either way, the sort of preferred habitat I would expect would be somewhere with normal air temperatures all around but plasma-involved machinery as part of the Great Spirit machinery, or general tech like running a welder. Versus living near lava. So, the higher temperatures would only be a problem if they got too close to large plasma sources; otherwise they would just prefer the warmth of being kinda near.
Agreed to ToA about The Powers That Be. It needn't be both serials per se (it's two that're unfinished, right? I should know this since I just prepared an appendix list for my retelling, soon to go up on my blog too, linking everything, but haven't actually had time to check the serials themselves again). You know the saying about "set achieveable goals". Doing two at once used to, apparently, be possible for Greg (I tried that kinda thing once but just got lost, so I only ever do one story at a time now). But maybe the problem of his free time isn't so much that he can't do what he used to (I'm speaking as I would if I was begging him to consider it, not that I think this is likely ) but that he needs to forget (for now ) about TYQ.
Aaanywho, as I said by PM before the topic, this is awesome news, and I really appreciate you taking the time to do this. Maybe I'm biased since I had a hand in it, but at the very least I'm glad answers were given and that they also got a nod of popularity.
For the record, when the winning magnetism option was proposed, someone (maybe me, I forget ) pointed out that if it were canonized, we could have some interesting theories about the MU: 1) that Mata Nui would impose a single magnetic field similar to Earth's, very weak so it wouldn't cost much power, or even more efficiently, 2) that many of the machines involved in Mata Nui's functions that "surface" at the islands would put off various mag fields as a side effect of normal operation.
If the former, Fa-Matoran would all innately be excellent navigators. If the latter (I kinda lean toward this just 'cuz it's more interesting) they would need to travel to familiarize themselves with the arrangement of these fields in order to be navigators but could eventually become adept enough (prior to that they would be able to head toward civilization if lost, etc.). It also occurs to me that Mata Nui might actually need a main field (extending beyond the skin a ways) to aid protection against stellar radiation just like Earth.
So, those theories aren't mutually exclusive. Perhaps if you want to imagine the higher story potential you could headcanon that the main field is weak enough that it would only be useful as a last resort if you were in certain spots where the stronger side effect fields don't happen to overlap. I would say the second theory is at least almost certainly true; it's a question (IMO) of the strengths and whether the first also is. Another possible factor is that the main drive system of Mata Nui might produce a single powerful field as a side effect (if it involved an electromagnet for example).
If both theories are right, then this may also give us a good theory as to preferred location -- any place that is both on land and where the local fields don't overlap (at the "event horizon" of wherever it becomes weak enough they could sense the larger field), so they would never feel lost in that area. Those two things coinciding should be rare; those spots should be a ways out from most of the big islands, so probably only a few spots on the continents, and tiny, distant isles.
Fa-Matoran have been confirmed not to have a preferred region, but I think most of them would steer clear of the Southern Continent since the electrical storms taking place in Karda Nui might interfere with their sense of direction. (Of course, the only named Toa of Magnetism is Jovan, and after his teammate used the Ignika he became the Turaga of Voya Nui. There are several possible explanations for this; one is that he disregarded the annoyance it caused because it felt was his duty to watch over the Matoran, another is that Karda Nui's shields stopped the electricity's effects.
Lol, I misread this opener as saying De-Matoran since you'd just mentioned them before. Okay, I forgot about that for Fa. Disregard the last paragraph before the edit (except for headcanon and fanfics if you like it ).
I might as well mention while I'm at it that if significant magnetism does get through, at least it would enable him to easily find the village if he ever left it -- "Head toward the strongest part of the irritatingly blazing magfield." Could also have been part of how he found the right spot for the original mission to the area.
Of course, who says that level would be an annoyance? What was canonized was "internal compass." There may be nothing like a sense of pain or even discomfort associated with it, although it could make for a more interesting story that way (and our equivalent, the sense of balance, can at least make us disoriented).