What male character is even worth pursuing if Lena doesn’t go for Ian?
Mike is a cheater
Robert is a wimp that constantly gets his ass beat
Jeremy is also a cheater (on Louise)
Axel is a crazy toxic asshole
Seymour seems really manipulative
Stan is a massive creep and a loser.
The only one I can see that might be worth it is Jack
That is a very interesting question. I will play devils advocate and make a defense for most of those people.
Mike: Yes, he is a cheater, but we have never met his girlfriend. We don't know that relationship history or its dynamic. There could be additional information we are unaware of. She could be really toxic or abusive in some way. A lot of people in a bad / abusive relationship will cheat as a way out of that bad relationship. We don't know if she has cheated on him before, or she is gold digger, or if she is using sex a weapon. There could be some sort of financial reason why they stay together. Like, maybe they own a home together, or rent the same place. It would be really hard for him to get a new place. This could of course all be hyperbole and she is a wonderful woman, but we just don't know her at all and don't know that situation at all to make an informed decision. As a general rule of thumb, yes cheating is bad, but there are exceptions to every rule.
Robert: The "Axel Fight" is just Axel sucker punching him. That's not really a "Fight", more so a "Sucker Punch". Both of the Ian fights can be avoided, and can go either way. So, it's unfair to say because a guy got sucker punched he is a wimp. Because at the time, he was sticking up for Lena. And that is ultimately what you want out of a guy if you are in Lena's position. Plus, just look at Axel. The guy is like the size of Hulk Hogan in his prime. Just because some huge dude who sucker punches you knocks you on your ass it don't make you a wimp. Furthermore, ones ability to be an MMA fighter is not exactly a key criteria when it comes to being in a relationship.
Jeremy: The thing about the Jeremy / Louise situation is that Louise is the one pushing for their relationship to be more than what it actually is. It seems like Jeremy only wants FWB with her, but she wants a boyfriend. Louise's inability to understand that he only wants to smash and isn't looking for anything committed isn't his fault. That is her own fault. She can't take a clue! They don't live together. He hasn't put a ring on her finger. He isn't whisking her off on some romantic getaways. He comes over to fuck her, and maybe sleeps over afterwards if he is too tired to go home. None of his actions towards Louise have indicated to her that he is serious about her.
Axel: Everybody likes to shit on Axel. He fucked up, and he will admit that. He will even apologize for it. He obviously still as feelings for Lena. However, she ghosted him. A lot of his actions can be attributed to guilt, and trying to make it right. When he punched Robert, I mean... From Axel's perspective Robert probably should have been minding his own business. He is trying to make things right with his ex, and some other dude comes up and is like, "Get out of here. She don't want nothing to do with you!" I don't think Axel is evil at his core. He misses Lena, and the times they had together. It is hard for him to just let go. He doesn't like how things ended. It can be very traumatic if someone you care deeply about totally shuts you out of their life.
Seymour: The man is absolutely ruthless, and will do anything to get what he wants. He doesn't care who he hurts along the way. He is a true psychopath, and he makes even Axel look like an angel. He is only slightly less evil than Ted Bundy. He is a very bad person at his core. Most evil person in the game. He could be Arthur from GGGB's best friend. They have the same sort of personality.
Stan: Okay your two arguments against Stan is that he is a "Creep" and a "Loser". Lets break these two down independently. He is not really a "Creep", he just doesn't have good social skills and he isn't very attractive, and a bit overweight. If he looked like a male model he would be "Mysterious" which is good, but he doesn't have the looks so it is thought of that he is a creep. He faces a lot of prejudice based on his looks and lack of good social skills. As for him being a "Loser" I am going to disagree there too. Because he moved out of his parents house, and he has a job, and he got an education, and doesn't seem to have any sort of drug or alcohol addictions. He is "Taking care of business" so to say. He is not being a NEET. Plus, in some lines, if Lena is kind to him he will genuinely makes efforts of self improvement. He is trying to self improve. So again, not a "Loser".
Jack: Jack has his own flaws. He is much more of a character in GGGB. So, you would need to analyze all the Jack lines from GGGB. I don't think he is a "Bad Guy", but he definitely has some serious stuff that needs to be factored in. The guy was running a strip club in GGGB. He also was willing to help Ashley bully Eva to death by humiliating her with her cheating video. Then you gotta realize he would do stuff like post pictures of Ashley after she asked him to keep it private. Then you gotta factor in all his drug usage. He isn't exactly "Husband Material" for these reasons and others.