During an extraction, the head of a Special Forces unit vanishes overnight, the second-in-command leads an impromptu search and rescue in which the unit are attacked by an adversary from an ancient and forgotten age.

The problem you're always going to face is that, without getting what you have in your head across effectively in your logline, the reader will have no choice but to make comparisons with existing material.

You clearly have knowledge of Nephilims and how you want this character to act, look, move, etc BUT if we don't then it makes zero difference. As I said previously, if the reader doesn't know what a Nephilim is, keeping in mind that your entire story is focussed around one, you're always going to have issues. This creature is the one thing that will set your story apart from others and if you're vague about it then everyone is simply going to imagine something that's already been done. All the best monsters stand out from the crowd. They're unique and they'd be described in such a way that creates a unique image in the reader's head:

Hulking patchwork of human parts.?Giant ape.?Man eating shark.?Intellectual and charismatic cannibal.?Creepy clown demon. I bet all of these immediately suggest a movie monster to you.

Simply put, make sure the reader's vision is as close to yours as possible.

Yeah, Predator vibes for sure but the vision I have is more grounded than expected. It's more like a modern day Western with a monster in it. Developing the Nephilim character, I did a bit of study on Nephilim and they were mentioned as being men of renown, legends of old which predate and could have given birth to mythological figure such as Hercules and Thor. The Nephilim in this, his nature is to war - I could see him first testing them then cutting off their food, then causing division among the group from the outside so they can be conquered. He lives to war and even though he may an imposing figure, I don't think I have to give up any intelligence or his cunning wit. I do want him to appear as if he is from another world with his size - when we think of giants today, we think of NBA stars like Yao Ming or WWE wrestlers like Andre the Giant. I want this character to be somewhat slim yet very strong looking. The image I have in my head would be a lot different from yours mike.

If I may: please, PLEASE, after taking feedback, do not alter the logline itself, but post each new version (perhaps with a new number) separately. I have lost the whole journey of the logline's transformation and it's a shame.