Of all the unpleasant qualities that Levi possesses, his pride takes the cake. What Levi wants, Levi gets, even if it means that he has to do immoral things, even if it means he will have to hurt the people around him to get it. That's just the kind of person he is. Pride is what defines him, as a soldier and as a person. His pride is also one of the major reasons why he lost many of his friends. A good example of this is the death of Farlan and Isabel. They died because he wasn't fast enough to save them, they died because of his pride, and they died because of his selfishness. The worst thing about it is that he blamed others because of their demise. He blamed Erwin for his humiliation that is the root why they joined the survey corps. He blamed the titans for invading them, and he blamed Lobov.
When he returned to the walls after the expedition, he sworn to himself the he will avenge the deaths of his comrades, he will make Lobov pay. However, Lobov is a powerful man and he can't kill him that is why, he used the second alternative, to make him suffer by hurting the one he loved the most – his one and only daughter.
The minute this thought invaded his mind, Levi was already in love. He was in love, they were in love. But no declarations of love were spoken, he was Levi, all the words that came out of his mouth were "inappropriate". He then makes up for it using action. The way they look at each other, the way they kissed, and the way they entangle their limbs together, it is the way they declare their love for each other. Petra never minds, for she accepted him the way he is. She likes to think that she already knew Levi, it was until…
"What?" Petra asks, tears streaming down her face, the words that came out of Levi's mouth were clear, but she refuses to understand it. Levi didn't answer.
"That's it? All those years we shared, they were all for nothing? Do you still love me? Because if you do, we can still…"
"Fix this? Petra… what if… I just don't love you anymore". Those words, they're simple but painful, in just a minute all the happy thoughts of Petra had, they were all gone, her heart was shattering and the pain was excruciating.
"I thought what we have is real, but you're awful, you don't know what love is, you never even spoke about it, but with your actions I thought you actually loved me, turns out, I was just delusional and starry eyed. I thought I already knew you, but I was wrong".
He just can't take it anymore, Levi can't stand this. "Will you please stop? You're so pathetic, Petra! Did I tell you that I love you? Guess what?! I never did. So, just shut the fuck up!". Those moments are full of lies. "There! I said it. I just used you, don't you get it? I'm a man, I have my needs".
Those words were sharp and it took a moment before everything sank in for Petra, she then told him words that shocked even Levi himself, words that he didn't deserve, words that made him think, 'what kind of evil person am I to even make a woman as good as her to weep', words that made him hate himself.
"How could you, Levi? I trusted you! I loved you! I can't believe this, and I hate myself for it!" She started pacing back and forth. "I love you so much." Her tears started streaming down her face. "But, if ending this 'pathetic' relationship would make you happy, then so be it. It may never be true to you, but for me it was the most genuine and natural thing that I ever felt in my entire life. Thank you for ruining everything. Thank you for tearing me apart. I hope this will make you happy." And with that, their relationship was destroyed. Petra walked away, and she never looked back, he didn't even stopping her ending their relationship. It's for the best he just told himself but deep inside, it tore him, twice the way it did to Petra.
Days have passed and others seemed to have noticed and started asking them questions. When Hanji asked Levi, he just shrugged her while she noted that they knew all about their unspoken relationship and asked him why, why would he leave a girl like Petra.
Weeks have passed and everything seems to be back to normal. Petra addressed him as her captain and she still brings him coffee, she still smiles at him and follows his orders. But the taste of his coffee is different, even though he liked it black, it was too bitter even for him, and her smiles were not as bright as they used to be.
The last to confront Levi was Erwin. He was always good at giving any kind of advice. "You should have told her the truth, but you made your choice and I will not question you about your decision on your own life, but let me just remind you and say to you the words you would always tell your subordinates, 'no matter what kind of wisdom dictates you the option you should pick, no one will be able to tell if it's right or wrong till you arrive to some sort of outcome, resulting from your choice' I just hope that you won't regret the choice you made".
Levi made his choice, and he chose vengeance over the person who loved him for who he was. He went to Sina and made the daughter of Lobov fall in love with him. It was easy for she had a crush on him; also, breaking her heart was easy and it was very satisfying looking at the devastated look on Lobov's face after his so called "revenge", and the best part of it is that amidst all the power Lobov possess, there is nothing he can do, for he can't be imprisoned for breaking someone's heart.
His plan took longer than he expected. Months passed and every day felt like an endless routine. Then one day, he woke up with a plan. When he returned to their headquarters, he was planning on telling Petra the truth and was hoping that they can recover what was lost. He was wrong, for he was too late, she already moved on with her life and found someone that will cherish her feelings and treasure her love. This is the price of his vengeance. He thought he can accept this but for some reason he can't, he became rude and he became colder. That is why Petra confronted him one night to ask him what his problem is.
"So what's the problem?" she asked.
Levi didn't answer.
"Captain…Levi, how can I fix the problem if you won't tell me what's wrong?"
"Petra you can't fix all the problems, and believe me you don't want to know what my problem is."
"Then what the heck is you problem!"
"Fuck! You really want to know?! IT'S ME! IT WAS ALL ME! I am the problem! Because I'm getting hurt even though I'm not supposed to, and I wish I could endure the pain that I am feeling, because I'm the one who chose this right? This is what I wanted. I hate myself! I hate myself for hurting you and for being so stupid because I let you go. You are the best that I ever had, and I just blew it all away because of my pride. My stupid pride! But right now I am willing to set it all aside." Petra was shocked when Levi did the most unbelievable thing, he knelt down. Tears fell from his strong grey eyes. For the first time, Petra saw another side of Levi, the Levi that she had been waiting for all this time. But Petra knew it was already too late.
Then, Petra said the words that would break Levi's heart "The problem with you is that you're so full of yourself. You're selfish and arrogant. No matter what, you are willing to do whatever it takes to achieve something even if it means hurting the people around you, especially those who love you. You always thought that you are doing the right thing, when in fact, you're just ruining everything".
She knelt down and took his hands, then stared to his deep grey eyes. "I'm sorry Levi. I loved you, I really did. You were my first love, but I guess our story ended when I realized that you love yourself more than you love me, even though you never admit it, I felt it Levi. I did." She gave him a warm smile. "And I am the happiest because of those moments, those kisses, and embrace and even in our quiet times. But, that was all in the past. Those bitter-sweet moments that we shared. I treasured it. I may hate you but that was before. Levi I forgive you, but that is all that I can give you".