The Omicron variant

Not quite. Even if that gain of fucntion stuff were true and that's currently more than a bit of a stretch, how it might evolve in the wild would have pretty much nothing to do with that. Contrary to popular belief a highly deadly virus is a crap virus as far as the virus' evolutionary success is concerned. The strain that would win Virus of the Year among it's peers would be a virus that had a very high transmissibility rate, with few or no obvious symptoms and the ability to spread asymptomatically, quietly reproducing in our bodies without killing the host at least at first. The Epstein Barr virus is a good example of a human virus that does just that. Something like over 90% of people in the western world have antibodies to it. On the other hand Ebola would be looked down upon when viruses have a christmas party. Too dramatic, only really transmissable when the infected are looking fierce sick altogether and kills most of its hosts.

If we look at pandemics in history they always fade away. Either because they've infected everyone and run out of hosts, or they become less deadly with time. Or both.

Due to the incubation time of covid-19 and the relative high % of people who are asymptomatic, I have no doubt in my mind the Nu variant is in most major cities now.

Maybe, just as likely maybe not. the Average incubation time for the Alpha variant was 5-6 days with 1% up to 14 days. The later doubly infectious Delta actually has a shortened incubation period of 3-4 days and an even smaller percentage of longer than that. If this Nu variant is even more transmissable because of a higher viral load again than Delta its incubation period is likely to be shorter again, or similar. Until we know for sure anything else is panic merchant territory.

For now, we just need to wait and pray this isn't a vaccine dodging variant, which is unlikely as the RNA vaccine boast the ability to block variants too.

Correction, all the current vaccines(as does immunity from previous infection), not just the mRNA versions boosts the ability to block variants. Indeed J&J a non mRNA vaccine showed a stronger response to Delta in the South African study.