After hugging Miss Fa Ya in the Roundtable Hall, she will give us a scarlet corrupt buff and a prop called curtain grace. After using it, we can get rid of this buff and restore the original blood volume.

In Eldon's ring, after we hug our little sister in the round table hall, we will get a scarlet corrupt buff, which will deduct our blood limit, but will increase our toughness, which is a very good buff for shield players. But for players of other routes, this buff is just a debuff that simply lowers the upper limit of blood volume.