One spelling error in 2nd paragraph, should be “thin black smoke”. Also you use “only” twice in 2 sentences next to each other.

I also felt the reference to the Amazon kinda took me out of the story. I was picturing more of a weird space adventure rather than something based on Earth. Kinda like the film “Treasure Planet” setting.

I’ve been reading The King’s English and I’m in a mood to critique grammar. I hope I don’t come across as overly critical – I do enjoy your story.

“Nikita took her role seriously, and went herself to scout out the nearby jungles for angry natives, but none revealed themselves.”

This sentence makes it sound as if Nikita did two things in a row: first, she took her job seriously and then she went to scout.

Rather than ‘went herself’, perhaps ‘went alone’ would be clearer?

“Deeper inside, Nikita knew that …”

Deeper inside than what? I recommend ‘deep inside’.

‘The Isle of Pezenat was simply mapped out by its shape. Terrain and woodland was unaccounted for on the map, only its location.’

I struggled to figure out your meaning here, particularly since you contradict it – is it only the location of the island shown on the map, or also its shape?

“thin black smoke smouldering from the side of its huge peak.”

Smoke cannot smoulder. The side of the peak may smoulder thin black smoke.