Beneath The Surface : Secret Of The Heart

there is a little family reunion. a girl who gives birth to 2 children. but her parents did not tell her. but the last one
is ill . so , they agree because that child will die soon. they took the another child to their father and said that female lead died...
It's a magical world. But nowadays the modern world . technology does a good job on magic. so they agree to do tournaments for each 5 , 10 ,20, 50,100 years. . .