True the ending felt really uncomfortable to me T_T Jake completely forgetting how much he suffered at the beginning and then also subjecting his only friends to that with no guarantee they will also have a happy(?) ending... With how he described the planet without mentioning anything about what happened, it also seemed manipulative and (as you mentioned) like he was brainwashed.
Like Jake was really lucky with Kashan, but I wish he would've still acknowledged how fucked up the system is and try to fix it somehow (maybe even together with Kashan and/or his friends) D:
Kashan mentioned in his inner monologue that the creation process can affect Jake's mind and the egg inside Jake will trigger his mating instinct so that the egg gets fertilized by Kashan's sperm. So if you simplify it, the egg is basically a parasite implanted by Kashan that is brainwashing Jake slowly.
Kashan mentioned to Jake that his body will change however Kashan deliberately omit the brainwashing part so that the egg can easily influence Jake's mind without any resistance.
Kashan is not innocent from this either but I still love a rich, responsible, gentle and caring alien husband. Jake had it better cuz he landed in the arms of an alien CEO but for the others? Nah idk abt that
This would've been less unsettling if the MC was some monster fucker who volunteered to be a surrogate for an alien lol.
The ending is actually dark and the way Jake is so brainwashed that being a surrogate is the best thing that ever happened is so unsettling