There are different types of assassins. What you suggested is a spy+Assassin combo. The story never mentioned she was one but clearly mentioned she never undertook any spy missions, definitely not something that required long term infiltration like the current mission.
They are given a target and they just take them down when the target is vulnerable like the game showcased in the early updates. She does stay emotionally distant when she kills and feels no guilt. But Alan isn't some random guy and anything related to him would affect her emotionally unless she is supposed to be that cold which she isn't.
She didn't sleep with Leon because of Revenge. Never once did she have a thought that she was doing it to get back at Alan. So why are you trying to make smoke without fire? She also doesn't know if Leon is a bad guy and sees him like a supportive friend before this even happened. He was the only who was there to support her. He seduced her plain and through despite her attempts at telling him to stop. That is clear proof she wasn't doing it to get back at Alan but got swept away under Leon's influence.
I still don't get why so many are raving that this happened because of a kiss when the game clearly planted it on our faces that so much more happened before the kiss.
This is definitely a story that involves cheating. I don't know why you are acting surprised when the summary itself says that it involves cheating. But how the cheating is handled or dealt with is the unknown factor. And there are good ways to handle it. Period.
So basically she is just a run of the mill assassin and not a top notch one. The skills involved make all the difference in being at the top or being average. Not every target makes themselves easily available and by calling her a top assassin means she can get to the difficult ones also which requires more than just sit wait and pew pew. Maybe it shouldn't have been stated she was top notch type thing as it would have avoided alot of the issues people are having with her breaking so easily. Maybe a promising or upcoming secret agent would have been better.
If not for revenge then why was the Kiss the even a catalyst that started the entire event? I don't think Seducing her is the right term if she was telling him to stop it would be more like rape, but she is a trained killer so she had to want it or she would have stopped him like she did before. Until the kiss she spurned Leon's advances, after the kiss she let it continue. It only takes one final thing to be the "straw that breaks the camel's back" Hence why it is being used as the trigger for the event. So she has no idea of his and her husband's past? She doesn't know what Leon's family did to his? Like I said she just gave Leon all the ammo he needs to make her a fucktoy for whoever and whenever he wants(cumdump wife anyone), unless she confesses to hubby about it and he just HAS to be ok with it for the story to continue. He'll be able to control himself unlike his trained assassin wife and complete the mission without issue(very unrealistic as not only did she betray him but with his enemy on top of it but he'll forgive and forget to make the happy marriage ending). IMO it would have been better if it was a more forced way but as it stands I don't see the staying married anywhere in the future unless he wants to be her cuck. Since the story is just beginning he's probably going to have to go through alot more cheating and probably have to watch as things get worse. On a positive note I'm quite sure she'll be satisfied quite a bit by the time the mission is over and probably have some new husband prospects. As for him getting Anne, besides her being one of the manipulators behind the break up, remember she still has the NTR option as well and unless you used a cheat mod or something similiar you don't know if that choice has been made already(possibly breaking her kiss early?). So it's quite possible he will get NTR'ed by her as well.
So let's say it wasn't for revenge she has now jeopardized the entire mission and her marriage to satisfy some urge of hers. I used jeopardized her marriage so people can keep the illusion of a happy ending that includes them staying married. The only thing I see about the way it will be handled is about his revenge or lack of depending on what the dev's choices allow. I'll refer to one of my posts above about the Corruption leading to a bad ending, so you'll only be allowed to do what the dev let's you, to still finish the story.
Never said I was surprised about the cheating that was the others arguing about taking the save the marriage path. I mentioned that said same path would be the cuck route. Really what good ways are there to handle a cheating spouse? Personally I have known 5 couples to go through a cheating incident. 2 split right off the bat. 2 tried to work through things but with the trust being broken it only made things worse. One could not trust the other and the smallest things triggered fights until they finally split 1-2 years later. Probably would have been better if they just broke it off to begin with but they agreed to give it a shot. The last seem to be ok until less than a year later it happened all over again. Once a cheater always a cheater. There is a reason why the vast majority of divorces are caused due to infidelity. It's not normal human nature to just accept being with someone you do not or can not trust and that has betrayed you. Doesn't matter the reasons which in this stories case is he can't satisfy her which means it will happen again she just can't help herself as we have seen. So the only way I see saving the marriage is to become a cuck unless he's just going to be in denial that she ever has or is cheating on him which amounts to the same thing. Unless some mysterious magic force gives him a horse cock to please her, she will never be satisfied with him sexually which means she WILL do it again because well she isn't satisfied by him.
The sad thing is I was really looking forward to playing this but the more it's discussed the more it seems to be just another Cuck story just with a mystery to solve in it. You can dress a cuck story up anyway you like to but it's still a cuck story. If that's case it will be apparent very soon in the story maybe 1-2 updates tops to know for sure. Unless they are all backstory based and no real story progression happens. Truthfully I hope I'm wrong and it gets better but with all the developments that have happened it just seems way too likely she becomes a cumdump and him a cuck until the end. It's not like the MC can stand up to Leon and say stay away from my wife since you have the behind the scenes manipulator so that whole being "strong" just means the MC has to suck it up and still be a cuck until it's over.
FYI I do enjoy being able to have a civilized conversation/debate with you. Most of these turn into name calling and stupid crap like that.