Fantasy book about demonhunters He did grow up outside the demonhunter "world" and went to a normal high school. At some point fairly early in the story a portal opens in his high school

[Mathias]

I read this book somewhere in the period of 2016-2017.
It's a fantasy book about a male protagonist whose parents were killed by demons when he was a child and he now lives with his aunt and uncle. His aunt and uncle are sort of demon hunter legends, as were his parents.
I can't remember if the MC knew about the whole demon thing, but I think he did. He did grow up outside the demonhunter "world" and went to a normal high school.
At some point fairly early in the story a portal opens in his high school and his secret is revealed and he then gets enrolled in a magic academy, where he is trained as a hunter/soldier. After he graduates he is stationed at a undesirable location because of some trouble he got in at the academy,
He ends up becoming the leader of said location, a captain I think.

There were more stuff that happened but this is the basics I can remember.

[Kris]

Mathias, does the guy have a sister with special powers as well (e.g., Mammon: Dark Rift Rising by J.B. Thomas)?

Is this book for young adults (teens) or older adults?

[Mathias]

Kris wrote: "Mathias, does the guy have a sister with special powers as well (e.g., Mammon: Dark Rift Rising by J.B. Thomas)?

Is this book for young adults (teens) or older adu..."

Afraid that's not the book. There is a sister-like character, but she is much younger than the MC and doesn't appear until about halfway through the book.
I think it was for young adults.

[Ayshe]

Jack Templar, Monster Hunter maybe?

[Mathias]

Mathias wrote: "Kris wrote: "Mathias, does the guy have a sister with special powers as well (e.g., Mammon: Dark Rift Rising by J.B. Thomas)?

Is this book for young adults (teens)..."

Sadly no.
The book I am looking for is longer and aimed at an older audience.

[Lobstergirl, au gratin]

Mathias, are you still looking for this or did you find it?