"The flow of time itself is convoluted..." Hmm. I wonder if the Ask Lake, with it's present archtrees and the Everlasting Dragon, could actually be a link to the past...to the Age of Archdragons. It wouldn't be the first that areas that are nearby physically turn out to be twisted in their reality of time and space within the lore ie. like how the "lands converge" in Dark Souls 3. Of course, there isn't much evidence to this theory, but the beginning cinematic suggests that all true dragons other than Seeth were killed and that the archtrees were destroyed. So, why are they here and how is such a large location with a wide open sky hidden away from view to the rest of Lordran (correct me if I'm wrong on that one)? Perhaps, like when we travel to Oolacile, time in the Dark Souls universe works as a traditional line, but all points upon that line are actually accessible if you know where to look/know how to access them.