WAW Zombies borrowed a lot of design from campaign because it was a side project, not because they were related. There is also no evidence that Nikolai ever actually met Reznov, and certainly none that Nikolai died in WAW. And as far as sources on YouTube are concerned, unfortunately, 98% of YouTube channels are misinformed and under-researched and therefore, virtually entirely inaccurate. And to guess that Reznov is controlling them is more far fetched than suggesting the devil is in the MPD. I don't mean to be harsh, just honest.
Ascend From Darkness has been a bit of a recurring theme in Zombies, with it originally referring, in WAW Zombies, to escaping the lower level of Nacht into the moonlight-washed upper floor where the best training spot on the map was located. Similar to the writing on the opposite side "Salvation Lies Above."
There have been countless speculations as to the identity of the Shadow Painting. None have been right so far. We really have no leads, and whatever it originally was has probably changed multiple times since Kino, if not dropped entirely, especially with the new twist the story is taking.