Layla's current condition kinda reminds me of FFXIII and the Crystal Stasis effect. Come to think of it, Lightning started off with a pretty similar motivation to Laura here...
What a satisfying punch to the face of a supremely creepy scumbag. Anyway, I'm glad this tried to be more creative for the protagonist's motivation and not use something tired like the ez-drama ol' reliable for revenge stories: rape. Instead her sister Layla got turned into something like a human shield battery, literally turned into an object and imprisoned until god knows when, robbed of her freedom and future. Not something I see very often in a revenge story; now I'm intrigued.