now that's another interesting find (but I'm lacking knowledge of Egyptian pantheon, so excuse me)
The symbolism of blue color of Nu might as well refers waters, just like other mythology, egyptian creation myth started when this very first god feeling lonely and he mast**b*t*d (duh) and his "water" become the gods and the worlds, it's pretty bizarre but roughly symbolizes concept "water of life".
Maybe the Nu(s) scattered in all periods are merely copy of spekkio, again he's character lacking background story, left us with analysis here and there. his name which means "mirror" in italy might refers (or pun?) how he reflected the strength of party, but also the fact he's created out of nothing (creatio ex nihilo). I always thinks whether End of time is practically the center of all time, it could be place of beginning, but also the end, which explains the presence of deity such as spekkio.
well maybe I'm overanalysing, but still make sense to be considered though.