You are the promise I made, by china_shop – 镇魂 | Guardian (TV) [Archive of Our Own]
“By the way,” came Zhao Yunlan’s voice from the couch, casual as anything, “if you can learn every power you see, do you happen to have Ding Dun’s talent too?”
Adult, first time. Shen Wei learns how Yunlan feels about him. Delicious, delicious smut ensues.