Reviews: Children of an Elder God
For me, CoaEG started shaky, got better, nearly crashed and burned during the Dreamlands chapters, then recovered well enough to merit reading to the not-ending. The final chapter (see the rec) brings the story to an appropriate conclusion, tying up the plot ends left dangling since '04 while bringing new levels of darkness to the setting. It's one of the granddaddies of NGE fanfiction, and that practically makes it a must-read, but of the Mythos/Eva fics listed on the rec page, it's the weakest overall in multiple ways.
The Dreamlands sequences were horrible, and felt completely out of place. One moment everyone is perfectly in character, and then people go to sleep and every character is a Possession Sue. Skip them if you want to read this. In fact, don't read this. The excellent buildup in the early chapters just isn't worth the dissapointment you get as you read on.
It is simply remarkable how well the Cthulhu Mythos meshes with Evangelion in terms of theme and tone. Cosmic horrors, paranoia, dangerous knowledge and fortunate ignorance, twisted bloodlines, forbidden and corrosive technology, insanity... It's such an obvious crossover I'm surprised it wasn't done in the source material.