SYNOPSIS:

The novel's background is that Nazi and Japanese research into the nature of reality in an attempt to access "magic" or create "ontotechnological weapons" (credit for the word "Ontotechnology" goes to EY) pretty much broke the self-sealing "reality bubble" of Earth, placed there by an interdimensional supercivilization fighting its own civil war for the Universe itself. That supercivilization's factions are perceived as "Angels" and "Demons"; they have made themselves into ontologically basic mental entities and the former are trying to impose absolute objective morality upon the Universe (which IS absolutely good and benign for any species that comes within its influence) while the latter are ruthless anarchists and opppose any rules at all, especially deontological ones.
As humans were predicted to have unusually strong reality-warping potential, Earth was sealed away in a local ceasefire that forbade both recruiting from it. After the "bubble" began to tear, the "demons", acting without any hierarchy, just spontaneously invaded, making some people into their playthings, dragging others away for use as psychic slave-soldiers and helping start WW3 in the ongoing panic. As Japan and the Reich, blaming each other, were preparing to obliterate the remnants of civilization, powerful technocratic elements on both sides independently launched coups, came to an agreement and instated a new world order that was essentially a megacorporation (I thought of this before reading any Moldbug). It shaped humanity into a great and complex hierarchy, where daily strife and the fullfillment of urges by the population would accumulate the "psychic" reality-warping energies in huge resonators to drain every drop of them, including from people gifted enough to become "mages".
The pooled energy was used to assist in brainwashing the masses, as a shield to keep rampaging demons away from the major arcologies, and to lash out at the barren and twisted Wastelands, where barbaric, Nietzchean sorcerer-cults now contended with each other and the infernal hordes. At the same time, there was a divine intervention as well. The "angels", before being driven out of our meta-region of the Universe by the disaster, took volunteers with especially strong psychic potential and moral fibre with them to fight in the endless war, while for all the other humans whom they found worthy - about 5-10% of the population after a century of life under brutal totalitarian regimes - they created a small utopian realm with impenetrable defenses near the North Pole. Founded upon some weird rules, restrictions and gifts, it's essentially going to be anime-like in my description. You know, heartbreakingly beautiful vistas, surreal technology like dragon AIs, ornithopters and crystal exoskeletons, an elaborate system of universities, guilds and knightly orders for everyone's talents to flourish, everything is always romantic, etc.

However, it comes at a price, as the trope demands; the ruling council is allowed to use utilitarian logic for hard decisions, and what they're going to do with it is my main plotline. The utopian culture sends agents Outside to help people and thwart the bad guys' attempts to penetrate their barrier or otherwise harm them, like Banks' Contact and Special Circumstances. And they support a network of resistance cells in the utilitarian megacorp's arcologies. Think like Al-Quaeda, but somewhat sympathetic and with Gnostic mysticism. The protagonist is a young soldier/technician in the Resistance, who starts out depressed, demotivated and Shinji-like (write what you know!); he's hopelessly in love with a female agent of the Utopia that's working with his cell on something top-secret. In the beginning, the cell is wiped out by a State Security raid and the agent is taken prisoner, but not before she implants the mortally injured protagonist with her hyper-advanced drone, making him into a superpowered zombie cyborg. Stumbling away from the wreckage, he meets up with a hacker from the arcology - who's part of a subculture stealing psychic energy and addicted to it - and that hacker's tsundere sister, a promising social engineer/spin doctor/brainwasher who's devoted to the megacorp at first but slowly agrees to become a double agent. Together they unveil a conspiracy involving a weird urban legend, said to be a memetic virus called the "Invisible Dawn" - which is the title of the novel.
Whew.