Underworld: the Holy Grail War That Started with My Younger Sister

Everything is to compete for the almighty wishing machine - the Holy Grail. A city with an ancient history, where countless magician families have launched brutal wars for the Holy Grail again and again. Chen Ze's parents died tragically after experiencing the last Holy Grail War, so Chen Ze took his sister Chen Siqing away from magic since childhood and lived a simple and stable life. At the beginning of the Holy Grail War, my sister Chen Siqing had a car accident and became a vegetative state. In order to save his sister, Chen Ze resolutely picked up magic again and participated in the Holy Grail War. But, is there something wrong with this Holy Grail War? "Are you my master?" The purple-haired woman in front of her is obviously the character in the game Iron Breaker - the Order of Nothingness Huangquan. How? Is the game also within the scope of your Holy Grail summons? While fighting for the Holy Grail, Chen Ze also discovered something more wrong with the Holy Grail War. It is no longer the previous seven servants fighting each other, but a war between a pair of thirteen, and all of them are fought by Ben Tie characters. How? Is there going to be a rebellion in this Holy Grail War?