I’ve Reincarnated Into the Older Brother of a Villainess That Was Fated to Die, so I Decided to Nurture Her to Change the Future

I, Zechs, have a little sister. Her name is Caron, and she is the cutest thing in the world. The problem is, at this rate, she will meet an awful fate. I know this because this world is the same as an RPG style Romance game I was addicted to in my former life, and no matter what she does, Caron will always die in the end. But I can't let my beloved sister die horribly like that! That's why I will change fate, no matter the cost--!