In terms of difficulty, even though there was only a voice, because this girl had appeared alone without another sister to serve as a control group, this should have fallen into the third tier of twin-distinguishing difficulty: independent of the world.
Yet over time, as they grew familiar with each other, Lu Man had gradually formed clear mental templates of seventeen- or eighteen-year-old Gu Lingyi and Gu Jiashuo in his mind, effectively coming with his own built-in comparison.
This essentially lowered the difficulty to the second tier: a fleeting shadow.
Chapter 115