As is no news to anyone here. According to the Character Material, there is a tone of doubt in the position of the OTR, both what title is written as:Ultimate One of Mercury?(水星(?)のアルテミット・ワン).
According to some theories, the OTR is not even a true specie of Mercury being, and the basis for this is in the Oort Cloud.The Ootr Cloud that is spatially close to the Solar System, is basically a small comet set where most of it is formed of pure ice, there are occurrences that usually comets that leave the orbit of the cloud, eventually fall into some belts and eventually on some planets(this supports the theory that the OTR actually >>fell<< on Mercury first, and also some people related that to the South American Gods who already have it dated).
But okay, and a more solid relationship between the OTR and this how is it? A lot of people think that OTR is actually an acronym for "Out of the name", which would be read by japanese writing as:名称のオールト"Meishō no ōruto".here comes another dump on the question of pronunciation, if you write the word Oort, and try to read it with the Japanese pronunciation, you will pronounce "ōruto" as well.
Still with this play on words, the kanji used to write Mercury are "水星" that can be read as "Suisei", which is also the same reading as the kanji used to write "comet", which are "彗星" .And the OTR nickname that is "Spider" is written with "ク モ" which reads "Kumo", which is the same reading for the cloud kanji "雲".
After the Meso-American gods we have proof that existences coming from comets and parts of space are possible. And Quetz, by the way, comments that she doesn't like spiders because in a past incarnation she has had a similar form.
I know this theory is relatively unfounded, but I wanted to share at least.