One of the best examples of an Eldritch Horror I've read

I’ve been rereading Project: Sunflower (in novel form) and I came upon this passage in chapter 29 (on pages 465 and 466 of the previously mentioned novel). Do note that this will contain spoilers.

Still... his curiosity demanded more answers, and his pride wouldn’t allow him to simply halt the expansion. He thought of Celestia’s reaction if he managed to destroy the menace, and decided to press on.

The swarm spread out, trying to determine the nature of this creature, seeking for answers. There were none. Malachite quickly grew frustrated, pouring more and more of his awareness into the center of the Tide, leaving just the smallest tether to his body.

Nothing. There was nothing beyond what he’d already seen and sensed. He began to withdraw his mind back into his own body when, with a shock, he found that he could not.

Something was holding him fast, pinning his mind. It had enveloped him without him even noticing. He expanded his gaze, trying to sense where the force holding him was coming from. What he found filled him with a cold terror the likes of which he’d never felt before.

The mind of the Tide pressed in all around him. He hadn’t noticed it for the same reason fish didn’t notice the water: it was simply the environment in which he moved, and it was too enormous to take in all at once. The Tide had a mind and a presence that stretched across the horizon, so enormous that he had less than the presence of a gnat before it.

And, now, the Tide was aware of him. It was as if the land itself, stretching from horizon to horizon, had suddenly reared up, alive and aware, and opened an eye ten leagues wide to look at him.

Terror gripped him and he tried to flee, to pull him mind back into his alicorn body, but the mind of the Tide held him firmly. He felt his consciousness being examined, not with curiosity, but with a systematic and clinical detachment.

No! he screamed silently, struggling furiously, desperate to get away. He sent a command to the far sprites he’d left in the signal’s source, trying to activate the inverse of the signal from before, hoping that doing so would instruct the nanomachines to work their way inwards rather than out.

The Tide stopped the sprites, studying them with the same passionless attention with which it had examined him. At the same time, Malachite felt his memories of the sprites, their capabilities and weaknesses, being examined by the entity that held them.

Then, with no apparent effort, the Tide stripped the swarm away from him, absorbing them all, taking the willing swarm into itself. The signal started again, and the nanomachines once again began to devour the Earth. His alicorn body, stripped of the sprite controlling it, fell on top of the Tide and immediately began slowly dissolving.

The pain he felt at the swarm being pulled away from him was nothing compared to what happened when the Tide returned its attention to him, calmly stripping off a part of his mind, his identity. Malachite screamed in horror as he felt an intimate part of himself stripped away by this... thing.

It examined what it had taken from him, apart of his awareness, his memory, without curiosity. And then the Tide swallowed it whole before resuming its examination of his very being. In short order, another piece of his consciousness was stripped away, absorbed into the Tide itself.