Akuyaku Reijou No Onii-Sama Wa Kouryaku Taishougaidesu!!

When I thought I was sick and ended my life without going to school, I reincarnated as the villainess Sylvia in the world of the game I played! I was trying to enjoy my second life with a strong body that can move freely. Due to Sylvia's older brother Rafis, she fails to avoid the ruin flag and both are banished to the "Forest of Death". Rafis begins to say that he will destroy his country for Sylvia in a severe sister complex..?! source: MangaUpdates