Obsessed with Saving my Twin Brother in Another World

What was much worse than living a miserable life? Jaune Sang thought he was one of the luckiest man living on Earth, he has a complete family, they can afford expensive things, and he has a twin brother whom he loves the most. But it all turned upside down in one night when his twin brother acquired a rare disease. In the midst of it all, his father was having an affair, his mother gone crazy, and the doctors said that there's no cure for his brother's disease. "Cosmo Delitrio", a rare disease that was popular on Earth back in the Middle Ages. Wherein a person's soul has been sent to another world due to the abnormal heat and ability. Since the physical and mental body can't handle it, as such, the soul needs to be refined and was brought back to another world. After Jaune finds out about his twin brother's rare disease, he knows he can't waste more of his time. Jaune is determined to save him! But what awaits him was something more—obscure.