Backstabbed in a Backwater Dungeon: My Party Tried to Kill Me, But Thanks to an Infinite Gacha I Got LVL 9999 Friends and Am Out For Revenge (Manga) Vol. 10 by Shisui Meikyou

Sionne's cruel human experimentation and the Soul Dragon's all-you-can-eat spirit buffet come to an end when Light serves up just deserts! Then he receives shocking news - his sister Yume is alive! Can the former 15th-level twerp come to grips with his near five-digit power level?!
Binding: Paperback / softback