What's the Name of That Book??? discussion

This topic is about
Knights of the Borrowed Dark
SOLVED: Children's/YA
>
SOLVED. YA/Teens Fantasy book about an orphan whose previously unknown aunt arrives to collect him prior to his birthday. Spoilers ahead. [s]
date
newest »

Details/Remembered Information.
Before I start, I must clarify that some information found her may be from book two, as they tend to blend together for me.
From what I remember of this book, the main character is taken in by his aunt, or an associate of his aunt, not long before his birthday. On his birthday, he manifest this worlds form of magic, which takes the form of a spark/ember. Or that's what its described to be.
the magic works as follows. There are a set of words from a language from another world that allow users to shape this magic. It must be spoken perfectly. Any imperfections can cause the magic to backlash at the user or otherwise harm them. Any use of the magic will cause the body to slowly be replaced by metal (Iron I think). It will start small, but the more its used, the more it happens. We learn this when the MC tried to use a word he heard from one of the people collecting him against something trying to kill him. He mispronounced the word and injured himself, as well as having a spot in the center of his hand become metallic.
In the first book, the main enemies are some sort of clockwork created pretending to be a person. I think they consumed the magic, or was otherwise after it. I think they killed the main characters parents.
Another key feature of the book is that in the basement of the orphanage is a girl. She is a creature from the world this magics words come from. She only appears as a girl. but isn't one. Near the end of the book, in exchange for the main character freeing her from the prison the clockwork people kept her in, she gifts the MC with the knowledge of all the worlds of the language their magic uses, as well as the ability to use them. She says she will one day ask for them to be returned, I think.
I remember that there was someone with metal eyes, who could maybe see the future. I cant remember. But they had metal eyes. There was a group of people with various metallic Parts. (Probably to distinguish their characters). If need be, I can share what I remember of book two, and I will endeavor to add more If I remember it. If there is anything wrong with this post, please Inform me.