MyLittleBrother
Surely in a world where they can make a fully immersive VR System, there exists a way to cure his illness. Medical technology and techniques go hand-in-hand with other forms of technology as they evolve. I'm hoping he'll be healed or on the mend somehow. Possibly, since he'll become powerful in this game, he'll earn enough money for treatment. He likely didn't have enough before to be treated, or at least, that's all I can think of.