Mysterious monsters without much explanation?

[Enkidoh]

Could be; could also be why there are so many fish-like mobs that float (Tempest/Violet Tides/really any beach).

Considering Bismark is intelligent and not just a beast, it seems very likely the case.

And another thing to remember is the fae were also shown to have existed back pre-Sundering, and presumed to be an Ancient creation too - a certain sidequest in Elpis shows a fairy (an Il Mheg fairy, not a SCH fairy which is not the same), under study, with the puzzled Elpis researcher assigned to study it at a complete loss to explain it or knowing who even who created it in the first place. And their puzzlement turns to utter bewilderement when said fairy soon turns into a beaver, causing the fed-up researcher to throw in the towel and tell the WoL "Now let us never speak of this again". So the mystery remained! (Presumedly the Ancient researcher quickly swept the records of it under the rug).

Even the infamous shoebill that popped up throughout ShB shows up under study in Elpis in another sidequest, and like the aforementioned fairy no one knows who created it or where it came from, and that in particular "resisted all forms of study" according to it's assigned researcher, but it did kind of pour cold water on the fan theory it was Emet's familiar (or at least a creation of his), as EW made no link of it to Emet in Elpis at all (if Emet did create it, the Bureau of the Architect would have naturally known about it, Emet did seem to be a stickler for following official protocol if nothing else, even reluctantly), so why it was shadowing the WoL throughout the First in EW is still unexplained.

So if the fae are Ancient creations, is unclear, but EW definetely makes the case for it.