Be it from something that I haven't read or something I didn't notice while reading the story, or is just hard to find, there are noticeable things that I'd like to add after finding out about this video that I'll post the link to below.
3:43 in the video
Since all lower gods should be comparable in terms of power, Diche should be upgraded from At least 5-B, likely far higher to 3-B, assuming that the barrier they created was a shared feat and could withstand Fastus's attacks, who is currently rated as baseline 3-A. This won't scale to Ras, because Ras only fought Incomplete Fastus.
Also, there's minor misinformation in the description for Fastus's Immortality (Type 1) and Self-Sustenance. The first star ever born is reference to Prima, so that'll be changed.
1:16 in the video
Now, for the new profiles - Prima and Nihilum, the primordial gods.
As for tiering and stats, both of these will scale above the rest of the verse.
Meaning that they'll scale above Notos, so they'll be At least 3-A, likely far higher and Massively FTL+ speed.
As for abilities:
Nihilum will get all of Fastus's abilities in his first key, because he created him alongside the other higher gods.
Prima will get Immortality (Type 1), Creation, Reality Warping and Incorporeality since he should have the basic abilities even lower gods possess as well as the abilities all transcendental beings have. On top of that, he'll also get Healing, Purification and Omniscience since the World Tree is a fragment of Prima (1:47 in the video).
I'll be back in a few hours, please let me know if there's something that I should add/change.