Hogwarts: Star of Bloodline and Vow

Transmigrating to the original generation of Harry Potter, Lin Yanqing's bound system only knows how to send emoticons and act cute??, and he's forced into a soul contract with the bat king, Snape. When a dark magic organization hunts them down with an evil mirror that can reflect souls, the two nemeses have no choice but to dance naked in each other's magic??.

"If the contract breaks, we die." Snape shoves him against the potion cabinet and roars, "If you dare to back down, I'll brew you into a love potion!"

But on a night when the mirror's light tears their souls apart, Lin Yanqing catches the curse aimed at him with his bare hands, chuckling amidst the blood: "Now, who is whose love potion?"

The shattered mirror reflects their wildly intertwined magic, and also illuminates the future--

Why does the Savior call Professor Snape 'Dad'? Why are there two pairs of wedding rings on Dumbledore's bedside table? And why does that baby with heterochromatic eyes possess the bloodlines of the two greatest wizards of the century simultaneously??

When all the threads of fate converge, they discover that this contract, born from conspiracy, has long become the most terrifying taboo in the wizarding world...