I didn't explain myself well, I meant if he/she had found some pointers or hints for his/her interpretation's basis or to piece together that theory.
I'm male by the way. XD
As for what I worte above, it's just a theory that I made up according to some hints I found in the game.
Necrozma is said to have come into the Pokèworld in ancient times.
How ancient we don't know, but I've got the feeling that it was way before Solgaleo and Lunala arrived at Alola.
Another thing is that Ulta Wormholes seem to be initially invisible to normal people's eyes (and probably only those who came into contact with the Z-Power can do such a feat), which means that the number of these portals could be potentially infinite.
To conclude, all that we know about the UB's appearances in ancient times and games' events are the following facts:
1) The first UB called Necrozma comes into the world by opening (intentionally or coincidentially) an Ultra Wormhole, but keeps its presence a secret and leads a life of seclusion.
2) The Z Power coming from the Ultra Wormholes created by Necrozma opens other portals, from one of which Lunala and Solgaleo come out.
3) After Solgaleo and Lunala disappear, the first invasion of Alola conducted by UB happens, giving origin to the legends that we heard from Burnet.
4) In modern times, Paver opens many Wormholes during his experiments, gathering information about the Ultra Space and the UB living in it, but he gets lost in one them, losing his memory as a result.
5) Guzzlord uses one of Ultra Wormholes opened by Paver and arrives at Alola, at Poni exactly, where Nau, Looker and their colleague face it in battle, repelling it away, but at an high price, as the female Faller dies in battle.
6) After that, Guzzlord probably takes refuge in Terminus cave, while Lusamine, discovering her husbands' documents, starts researching the Ultra Wormholes, in order to get her husband back, only to be infected by Nihilego's neurotoxins and becoming obsessed with the UB.
7) Type: Null is created in order to face effectively the UB, but the program comes to an halt when Gladion takes the Pokèmon away from the Aether Paradise.
8) Lusamine is enraged and because of that she uses the Cosmog left behind by Paver to further her reasearch, only to force Lillie to escape with the little Pokèmon.