So this might be a little longer because this is more descriptive than the other story and i actually rewatcted the anime just for this so enjoy...
[ 3rd Person POV ]
Year 845
You were an 11 year old boy, your happy with your life. But it will change one fateful fay. You were outside playing with your friends. The smart one Armin Arlert, the beautiful and stong one Mikasa Ackerman, And the Hardheaded one Eren Yeager.
After the four of you finished Playing you guys would talk about the scouts and the outside world. Then it happened. There was a loud explosion accompanied by a blinding light and the ground shook.
Townspeople were leaving there home to investigate and a couple of people were piling up in the streets. The four of you went to the crowded place to see what was happening. And there you guys saw it a large hand was on the wall then seconds later a large head appeared.
Then like instantaneous the large behemoth kicked the wall. Debris flew over your head and townspeople panicking and dying left and right.
It was only when someone hit you that you snapped out of your trance and started running. Few minutes of running then you realized that your not with your friends anymore. You tried going back but your father took your arm and dragged you back to wall maria.
Timeskip
You were on a boat ( the one that was ahead of eren's boat ) you looked back to the wall. that's when all of a sudden a large titan burst through the wall like it was nothing. You saw townspeople began to panic and started to jump to the ship behind yours.
Your mother covered your eyes to not witness the horrific sight of people getting eaten. You just prayed that Armin, Mikasa and Eren was still alright.
A camp was made in the district of trost but you and your family left to go to the district of Karanes where your relatives resides. You still didn't know if your friends were still alive. You pushed your self to join the cadets and become a scouts.
Year 847
You enlist to be with the 104th cadets. There you reunited with your friends you were happy to see them again.
Timeskip graduating time Year 850
You placed 7th in the division and all the troops celebrated after that. After eren gave his speech the four of you went outside and talked about the outside again. The great and vast Ocean.
You thought your life couldn't get any better your with your friends again and just having a good life. But you actually don't know this but Mikasa actually has a growing obsession over you. It started when you joined the cadets, she just couldn't stop thinking about you and over time she obsessed over you.
(Sorry couldn't think of any better way)
Then while you were cleaning the cannon with eren and the other cadets. A flashing light appeared right infront of you guys. And then the same titan appeared dubbed the colossal titan. All of you guys got blown off and the gates was kicked open. It's the repeat of five years ago. While hanging on the wall you saw eren go up and tries attacking the titan. When you saw this you got motivated and followed him.
But when he got up the wall it was too late.
(Y/N): Eren! Where'd it go? Did you get it?
Eren: No it disappeared.
(Y/N): Come on let's report.
After the meeting you got assigned with armin and eren at the vanguard while mikasa was with the elite.
You were about to leave when you felt a hand grab you, you turned around to see Mikasa.
Mikasa: Y/N please don't get hurt out there. Please come to me when your in trouble I'll protect you ok.
(Y/N): Y-yeah Mikasa you too keep safe.
You two separated and went to your own divisions.
Timeskip
[ Your POV ]
I was with eren and armin when Thomas got eaten. Rage overcame eren and he attacked the titan we tried to stop him but it was too late. Every single group member we had got eaten it was only me, Armin and Eren.
And that's when i realized that this place is hell and this titans are the demons. Then it happened i saw eren got bit on the leg severing it and he dove through the roofs. I then saw armin stumbled back on the roof and he didn't saw the titan near him. The titan was about to bite down him that's when i swoop in and got him. But that's when i realized my left hand got severed on the process i pushed armin on another roof. Then i was grabbed by another titan.
' So this is how i die, i never got to tell krista how i felt about her. Well what a shame well at least I'll be out of this hell hole once and for all. '
I was on the tongue of the titan when all of a sudden Eren grabbed my hand and threw me out. Then in a flash he got eaten.
My vision darkened because of the blood loss and i blacked out.
Few minutes later i regained consciousness again. I saw i was on a rooftop with armin beside me i saw the other cadets were also there. Armin filled me up on what was happening they were all almost out of gas. And the supply team is under siege and then i remembered about eren i just sat there with my head down.
And out of nowhere you heard a familiar voice.
[ 3rd Person POV ]
Mikasa: Armin! Y/N!
She came closer to you two and she gasped when she saw you lost your left arm.
Mikasa: Y/N! What happened to you.
Armin: Y/N lost his arm because of me mikasa.
She shot a menacing glared to armin.
Mikasa's Mind: i should've known my love would get hurt i should've been there. No it's not my fault it's this bastard Armin's fault for endangering him.
Mikasa: What about eren?
The two of you just stood there with silence that's when she knew what happened.
She then took you in her back and lifted you up with inhumane strength. Then she made the speech (the one from the anime) and took off all the other cadets followed her lead. She then stopped on a rooftop and everyone followed her lead and all stopped.
Mikasa: Jean, you take the lead i need to go somewhere with Y/N.
Jean: Wait what.
After he said that mikasa left you were left confused, you tried asking her but she didn't answer and continued her way. You were persistent on asking her then she had enough and knocked you out.
Few hours later you woke up and saw you were in an unfamiliar room. You tried getting up but you were bound by chains. You began to panic then you heard footsteps come your way. Then the door opened you looked at the door and to your shock it was mikasa who was standing there.
She had bloodstains in her clothes and a serious face. But after she saw you had woken up her serious face turned into a cheerful one.
Mikasa: Y/N~ you're awake that's good.
(Y/N): M-mikasa W-why are you doing this!?
Mikasa: Why? Because i fucking love you Y/N.
You then began to silently cry,
Mikasa: Aw Don't cry Y/N, hey look her.
You looked towards her and she was reaching for something in the bag she was holding. She then slowly pulls something up and to your horror it was Armin's head.
Mikasa: Look, it's the one that hurt you, i killed him.
She said with a crazy tone, you began to cry more when you saw your friend's head.
She then walked towards you and laid next to you, hugging you. You just silently cry there because you know there's no escaping from her.
The end
Not my best again it only had some Yandere part I'm sorry for that