Story is post apocalypse modern world, humanity has been declined with a monsters that suddenly appeared.

The monster have grey skin colour and looks like bionic chimera or something, that destroyed and killed many people.

Mc was 15 or 16 years old boy, his parents already die and he is taking care for his 8 or 10 years old sister.

He live in destroyed city, food and drink are scarce there, and he resort to steal it from some mafia big shoots from the city.

He got caught, he beg for mercy saying he doing it for his little sister and if he die, nobody will take care of her.

The mafia leader then give mc a chance, to retrieve something in another city. That city has been destroyed and the nest of the bionic grey monsters.

Mc then goes to truck along with 5 people who have problem with the mafia like debt or caught stealing like mc. They dropped mc and the 5 other man.

They got surrounded and mc noticed the monsters are blind and sensitive to sound. He tells other people to not make noises, the other 4 decided to sacrifice 1 guy by stabbing him , he screamed and the monsters attention drawed to him so mc and the other 4 people can escape.

Mc was kinda mad and ask them why they are doing it, the other 4 people say it is how the world works, to live they need to sacrifice others and tell mc to shut up.

After that little by little their numbers got dwindled, mc then get pushed as bait, till a woman having a steel wing falls from the sky.

The woman then killed the monsters with ease.

That was the summary for chapter 1 or 2 ...i read it in 2016 i remember the title have steel or iron wing in it but i cant find it.
It was korean webtoon btw

Unfortunately I can’t tell you what manhua that is but you have one hell of a memory my friend!

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Skee Skee

Valkyrie Agency?

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~4400 manga completed
~1700 ongoing...

yes it is thank you very much