Well, as for whether Tsumiki gets with Io in the manga, the answer is no. The story takes a different direction for their relationship, leaving it open-ended and full of possibilities.
One great science fiction book on io9 could be 'Dune' by Frank Herbert. It has a complex and immersive world-building, with political intrigue and a unique desert planet setting. Another could be 'Neuromancer' by William Gibson which is a classic cyberpunk novel that really set the tone for the genre. And 'The Hitchhiker's Guide to the Galaxy' by Douglas Adams is also likely to be on there. It's a hilarious and imaginative take on space travel and the universe at large.
In Greek mythology, Prometheus was a figure of great significance. He was chained to a rock as punishment for stealing fire for humans. Io was a beautiful nymph who caught Zeus' eye. Zeus transformed her into a cow to protect her from Hera, but Hera was not easily fooled and sent a gadfly to torment Io. The connection between Prometheus and Io could be related to the overarching theme of the gods' power and the suffering they inflict on mortals. Prometheus' actions were about the elevation of humanity, while Io's story was about the arbitrary and often cruel power of the gods over the lives of those they desired or saw as threats. It's possible that their stories were both examples of how the gods' actions had far - reaching consequences for those involved, whether they were trying to help humanity like Prometheus or were simply victims of the gods' whims like Io.
Overall, the translation of a-channel manga into Portuguese (Brazilian) is decent. Some parts are smooth and accurate, while a few complex terms or cultural references might not be translated perfectly.
You could have Io start out as being very distrustful of Percy and the demigods. She has been through so much with the gods chasing her that she is wary of any new beings. But as she spends time with Percy and sees his good heart and his determination to help her, she begins to open up. By the end of the fanfiction, she has fully embraced the idea of being part of the demigod world and is ready to fight for its safety, which is a significant transformation for her character.