Eternal Life

For years, the Khan's only disease had been 'old age.'

He was very old now — too old even to recognize all his great-grandsons. But his body was still strong; even if he was 'lying in bed', it was not because he was 'ill' but rather because he was fighting a protracted and costly war against death of which he disregarded any costs for his desired outcome.

The main force fighting his 'war' was originally famous doctors from all over the world, and this was also coincidentally the main reason why everyone thought the Khan was 'seriously sick.' Over time, even the Khan himself believed that there was some mysterious disease inside him, a vanguard of death. If he lost to it, he would directly face death; if he could defeat it, it would help stop or even frighten away that cruel enemy.