I read a few fanfics of Marinette's friends getting disowned by Marinette by trusting a liar instead of believing Marinette's side of the story, I don't see much with having the school go through anti-bullying lessons. Every school has this for a reason and its always important for students to learn what a bully, sexual harassment, and stranger is for the safety of awareness. The show lacks of this for reality but its for kids show. Instead of having Marinette disown her friends, try writing a chapter about the school needing project lessons about bullies.
I've been taught alot about what a stranger is by my sensei years ago and it did gave me safety awareness. Even at my school too about harassment and anti-bullying too for the safety of students. But yes, trust is very important because if your friend did something bad to you, it requires to learn to trust them again which takes a very long time to ear that trust or not. My friend and I online had to deal with our ex-friend years ago who makes up so much lies to us, we could no longer trust her anymore and we had to cut ties with her since she can't be honest or sincere with herself. It made us feel like we lost faith in her. But for the safety against manipulation and toxic relationship.

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At school, although their classroom teacher wasn't fired but she received something else to help teach her students about bullies and harassment since this was the school board director's suggestion. For the safety of the students to be aware of bullies and harassment. Chloe, however, had the power not to get suspended for aiding a pathological liar. It would only get worse when she's around due to the mayor's orders but unaware that his wife Audrey is blackmailing him that if he lets the school suspend her, he will get fired from her. Alya and Marinette's relationship has started to get better. Despite Adrien's father giving him strict orders to never be with commoners like Marinette.

But still, Adrien wanted to be with his princess rather than having what his father wanted best for himself instead of what Adrien wanted to do with his life. As far as he checked his facts between his father and Monarch, Collector was never at the character selection from Gamer 2.0, or at the time when everyone got scarlet akumatized, he wasn't there. Which gave away they are the same to him now. Whenever Lila is not around, it is as if she is observing people like him, his father, and his girlfriend in possible disguises.

"Now class, I know these last few days we've been taught a lesson about bullying and deception the hard way thanks to Cerise Bianca" Miss Bustier began.

"Heh, that last name doesn't sound like a real last name when it's a real first name," Nino said.

"It means 'white' in Italian, Nino. But one thing for sure she is Italian than just a liar" Adrien reminded him.

"Whoever she is, she's a mystery," Nino said.

"And that's another mystery for all of you to stay alert and never talk to strangers you barely know. Everyone is a stranger" Miss Bustier hands out papers about what is a stranger.

Every student read through them, and Marinette easily identified how someone like Cerise would act.

"Now who can tell me what a stranger is?" Miss Bustier asked.

"It's someone you don't know and could at any time take advantage of you" Rose raised her hand.

"Correct. Anyone is a stranger to you. I'm a stranger too because I'm an adult but also a mother soon to be. Every list of things involved in strangers you come across" Miss Bustier said, giving a slideshow of the list of things we shouldn't do around strangers.

Don't talk to strangers, don't take anything from strangers, don't go near strangers, and definitely don't be naive to strangers. The students wrote them down by note.

"It's very important like with phone spammers and trolls on social media. Always be careful who you talk to. The reason is because you're all children with less experience. If a stranger grabs you, what do you do?" Miss Bustier asked.

"We'll just call for help if anyone's nearby?" Kim guessed.

"No, you shout. If you're in public, at a store, anywhere with people around you, you scream to tell the stranger you're not his relative or anything. Shouting gives attention and it makes the stranger to back off. For you see, kids at a young age are not strong enough to fight a very grown adult" Miss Bustier said.

"Got it," Kim wrote it down.

"Ridiculous whiny weaklings" Chloe scoffed at this boring session.

"Suit yourself like you did with Lila, Chloe. Like a stranger she was, she did try to manipulate you" Adrien said, teaching her about how foolish she was to trust a liar, "Face it, Chloe, she was gonna use you as a pawn until your usefulness has ended" He added.

"Pathetic of you, Adri-nothing. People adore me" Chloe scoffed.

Adrien didn't reply, he remained focused on the lesson. The next was about a bully and of course, everyone glared at Chloe who is an example of a bully.

"Now, what about a bully?" Miss Bustier asked.

"It's someone who picks on anyone to feel more superior," Marinette said.

"A person who makes someone's life miserable without facing the consequences of their actions" Adrien glared at Chloe, for what she did to Marinette last year before he came to school.

"Like seeing their victims as only garbage" Marinette added.

"A person that likes to torment others for their entertainment," Alya said.

"And even force others to do their dirty work, that's a cowardly move from a bully," Nino said.

"A bully can also encourage victims to...kill themselves which is a bad sin. Especially for the victims' parents to lose a child can be very grieving" Juleka muttered.

"That's precisely the worst thing that could happen, Juleka. Bullying affects the victim both physically and emotionally. In fact, sometimes the bully victim might become a bully themselves" Miss Bustier said.

"Ridiculous. Utterly ridiculous" Chloe said, especially how Sabrina is reluctant at times.

Marinette just glared at Chloe. She knew she wouldn't change. Adrien himself proved how wrong he was about Chloe who could change too. Especially how stupid he was to believe she wasn't useless until now she makes bad decisions for her life by trusting a liar. She just became Cerise's pawn the same way Shadow Moth used to pretend to be generous to her when instead manipulating her.

After class was over, students made sure to study about this so that no victim gets akumatized. They know many times Chloe never learns her lesson every time an akumatized victim seeks revenge on her.

"We better stick together on this one," Adrien said to Marinette.

"Yeah, to spread inspiration," Marinette said.

"Chloe won't change at all. She's lost to herself in her dark heart" Adrien said, losing the only first friend he had as a kid.

"She's too much like her mother," Marinette said.

"Her mother left for New York years ago. It's the same as how I lost my mother over a year ago but I never take it out on anyone who has a mother" Adrien said, going to his locker.

"Chloe did it the wrong way," Marinette said.

"Well, some people try to choose a good path, some choose a bad path. I choose a good path to honor my mother. She wanted me to be happy and move on from the past that I used to have" Adrien puts his books in his locker, "Unfortunately for Chloe, she only chooses to honor herself with no one in it. The reason she doesn't treat me like shit is because I'm from a rich family. But that doesn't mean I want to be the next wealthy person in the bloodline" Adrien closed his locker.

"You really got a strong spirit, Adrien" Marinette said.

"Thanks. I wish I had your confidence, my love. Back in my world, I always focus on being perfect" Adrien said.

"Well, nobody is perfect," Marinette said.

"Yeah, you're right" Adrien smiled.

"Getting good grades is hard. My father expects me to get an A+ in everything" Adrien said.

"A C is not a big deal," Marinette said.

"To him it is. Like the time I thought Lila needed help with calculus, it was a lie just to take a selfie picture with me as a souvenir without my permission" Adrien remembered how she left the mansion in a hurry and got Nathalie and Placide in trouble.

"Oh jeez. I just hope she stays in the asylum. I'm afraid if she somehow escaped" Marinette got worried.

"I heard Cat Noir is very protective of you. I'm glad he makes a great knight for you" Adrien chuckled.

"A purrfect knight" Marinette joked.

"Funny. Anyways, I hate heading home. If my father doesn't support us, then I guess he lost his title as a parent" Adrien said.

"If child services could do something," Marinette said.

"He's a powerful man, Marinette. He's got lots of authorities and agents for that" Adrien said.

"Oh great" Marinette sighs.

-

In the asylum, Cerise was sitting locked in, the guards not listening to her lies.

"That cursed Marinette must pay for imprisoning me! She will pay dearly!" She ranted crazily.

Unfortunately, it was her own fault she created this mess to torment Marinette to almost lose her friends. Instead of being honest with herself like Adrien told her to be, she chooses not to be sincere and all trouble is caused by her. Not Monarch, not Marinette, not Adrien. Her, and only her. She just couldn't stay out of trouble and learn to let it go. But she could only blame Marinette for her own failure.

"Get up! You got a psychiatrist appointment!" The guard said, making sure the cell was secured with electricity shock if she tried to escape.

"Leave me be," Cerise said coldly.

"This is the first patient to refuse to get better. These pills we give her, it's not helping her" The guard said to the psychiatrist.

"Grab her, she's going to her appointment!" The other guard said as they grabbed her.

"LET GO!!!" Cerise punched the guard but the other tasered her and she went limp on the floor.

"That brat is such a pain in the ass" They carried her.

"It's her own undoing for this, sir. Her well-being is already destroyed by her own selfish benefits" The psychiatrist said, learning full well that Cerise's lies destroyed her mental health.

As soon as Cerise is put in a straight jacket to not fight any more guards, the psychiatrist hopes she can cooperate well. Professional scientists did give her a truth serum drug to make her responsive in telling the truth but other times the drug had side effects on her. Sodium thiopental drug can be a little lethal which was why it was banned years ago. But for now, Cerise never wants to be truthful at all.

"Now let's begin Miss Bianca," The psychiatrist said.

"I rather not" Cerise refused.

"Don't make this more harder than it is" The psychiatrist said.

"You think you know me? My life is empty. I don't feel anything" Cerise said harshly.

"I heard you were once a movie star as a child until you were disbanded from ever acting again. It seems you feel like the world abandoned you. It's like self-loathing until you learn the opportunity to pathologically lie to gain the center of attention but at the price of becoming a con and a fraud" The psychiatrist explained her condition.

"None of it matters now," Cerise said.

"To you, it will because pathological lying is only destroying your well-being. Not only will you get attention from it but more so in creating enemies for yourself. Every fake identity you create only leads you to being a fake person instead of your real true self. Lying constantly to everyone will only have them not believe your real words anymore. Similar to a boy who cried wolf" The psychiatrist explained why lying can be dangerous because it will lead to no one wanna trust a liar.

"So I've heard," Cerise said.

"So you were aware of your actions and consequences but not your well-being. Pathological lying can be bad for mental health if not treated on time. The more you lie, the more you become inhuman to yourself and of course, making lies can turn into disaster. Like that girl Marinette you are obsessed with to ruin her life. Your target became an irrational obsession" The psychiatrist said.

"She was the first to see through my schemes. Adrien knew too but kept quiet and thought I wouldn't do much harm" Cerise said.

"She had every right you know. Although I heard she did say she would have been friends with you if you stopped lying to her friends. Even Adrien also said to you that you can count on him but not if you hurt the people he loves. I suppose you couldn't handle keeping a promise to him and you violated his trust for you. For you see, he now experienced how you became worse and your influence on his friends really caused a lot of damage" The psychiatrist explained why sabotaging the relationships can be disastrous, "Instead of making friends, you only turned against them"

"Ladybug also confronted me about it and I felt humiliated!" Lila shouted.

"Did she apologize?" The psychiatrist asked.

"She did but I never accepted it," Cerise said.

"Forgiveness is something to learn, Cerise. Unforgiveness will produce bitterness and bitterness can be directly traced to the failure to forgive. It can make you caustic, sarcastic, condemning, and nasty. Forgiveness is a practice of empathy. If a person who doesn't forgive others will not be forgiven by God" The psychiatrist explained why forgiveness is important in life.

"No one forgives me. Which is why I don't forgive anyone" Cerise did not care about it.

"You had so many chances and you just throw them away. It's no wonder you manipulated everyone. The same way Hawk Moth manipulated his victims, including you, to do his bidding. I suppose you don't know what that's like when someone makes pathological lies about you" The psychiatrist said.

"Not at all," Cerise said.

"How would you feel if someone made false rumors about you? The same way you falsely made lies to a classmate?" The psychiatrist asked about it.

"Horrible" Cerise replied.

"Exactly. Just like you used to lie about celebrities, it ruins their reputations and they don't like that. Now, I want you to understand this because from what you did with a fake name, you were indeed a fraud in everyone's eyes. Fake identities can be very illegal" The psychiatrist said, knowing that Cerise is mentally unstable.

He left the cell, knowing the doctors would give her more pills to come to her senses.

-

Marinette was at home, looking at the latest news about Cerise. Every therapist and psychiatrist says that Cerise has an obsession to get revenge on this classmate who was akumatized to expose her true colors.

"I just hope that creep won't escape," Tikki said.

"Basically it is my fault for confronting her the first time as Ladybug, I made an enemy for myself" Marinette acknowledged how irresponsible it was to use the miraculous for personal gain but she hated liars.

"But you did save Adrien from seeing she was a liar," Tikki said.

"Yeah, I did" Marinette replied.

---------------------------------------------------

I'm no psychiatrist but I do go to my therapy sessions to overcome my trauma. Its just I have knowledge in knowing the consequences of every action, especially with pathological liars and bullies who do bad things and what it can do to their well being and mental health.