Both are GL stories. In LOY one of the FLs is half demon, in THYL she is a demon cult leader, while the other FLs are both cultivators with hidden power. The special of LOY and THYL both have the couple meeting again after hundreds of years.
“Legend of Yunze” is a Chinese censored GL (but with a lot of chemistry and glances and mini touches lol) wuxia series whereas “Couple of Mirrors” is a Chinese censored GL romance too! :)