Sorry, I don't have the specific name of the author of the Ennead comic. Maybe you can look for it on popular comic forums or websites dedicated to comics.
One common theme is the exploration of their different backgrounds. Cyno from the desert and Tighnari from the forest have distinct cultures and ways of life, and fanfictions often explore how they bridge that gap. Another theme is friendship turning into something more. They start as comrades and gradually develop romantic feelings.
The best place to look for the ennead manhwa raws is on official manga sites or authorized distributors. However, if those don't have it, you could explore some lesser-known manga aggregator sites, but always be cautious about the legality and potential risks.
There's a really interesting Cyno x Tighnari fanfic called 'Under the Sumeru Moon'. In this story, they are on a mission together to solve a mystery in Sumeru. As they work side by side, their feelings for each other start to grow. It's full of mystery and a bit of action, which makes it very engaging. Also, 'Harmony of Elements' is a fanfic that shows how their elemental powers interact and how that affects their relationship in a unique way.
The English version of Ennead manhwa could potentially be available on well-known manga subscription services. It's worth checking a few of those. Or, you could try looking on social media groups dedicated to sharing manga, but again, be cautious about the legitimacy.
The son might initially be very confused and resistant. He has his own sense of identity as a boy, and being forced to be a girl goes against that. He could try to rebel by doing more boy - like things in secret.
On the other hand, the son might try to adapt in a way to please his mom at first. But as time goes on, he will likely start to feel a great internal conflict. He might start to secretly explore his true identity while still pretending to be a girl for his mom. This could lead to a lot of secrecy and emotional turmoil within him as he tries to balance his true self and his mom's expectations.