.... Plus easiest way to expand an empire is through marriage, already got Helion locked, time for more.
ha ha ha ...ok dude, It was meant as a tease... so if you can't take it as a joke, I apologize... there.
As for the difference in the girls, no I do not think Nyobi is "hot." She was raised by the Krillen, has a blood lust a mile deep and a tyrannical urge to dominate the sector...besides being a first hand killer. The package may look pretty but there is a reptile inside. Something we guys have got to learn to spot or women like this will do us in and spit us out...in real life.
Kara is an entirely different person. Raised by a wise and gentle master after losing her family she has shown nothing but 'common sense' and compassion for those around her. A trained killer, yes. But because she's dangerous means she can choose to be peaceful...and would prefer doing so. Yes She's an excellent lover but she's nothing like Nyobi.
Breana is another situation and IMHO I think it is just circumstances that rules out marriage between her and the Captain...ever.
So while expanding the empire through marriage is great...if your goal is to expand the empire... do you really think that it the MC (Main Character)'s real goals in life? Do you think he's got Helion 'locked up'..? Are you assuming he'll end up with Lia then? ...or does he want to? He's got lots of choices, doesn't he? Which you will find out in the final version update when it comes out...in a few months (quality updates take time)
And finally, I did have an answer.... it's down at the bottom of my reply.
So I hope these thoughts clarify something about the Callisto game and Universe. What I love about it is it is NOT primarily a 'let's see if we can f*ck all the girls and get a harem' purpose game...it is an adventure saga with lots of action included...with real characters, plot twists and great adventure. So if, as your comment insinuated, you'll be disappointed if you don't get ALL the girls in the story, I'm sorry, you'll be disappointed. I'd think six regulars and several more on the side would be enough for any guy...but, hey, I'm weird. So I hope you enjoy the game in spite of being disappointed.