Both MLs are royal and should be on the throne as emperor but due to some circumstances are instead a wanderer. In childhood, both MLs were afflicted with a cold poison that now becomes life-threatening, and the FL must find a cure. Both FLs have a complex relationship with their parents and experience personal growth, going from an isolated life to seeing much of the world.
Both series are fascinating to watch, with incredible plots and likable characters. Both female characters are strong-willed and intelligent in their ways. Thus, at first, they tend to be cold and distant to our female lead, but as time goes by, they lower their defenses. Both male leads (Nangong and General) were oblivious to their female lead at first, taking them as a spy sent by authority/someone with power but will eventually trust them and fall for them.
Both are set in a historical/fantasy world in which people have magical powers and abilities. Both FLs are unique in some way, and the MLs have something special about them that helps the FL (gives her magic vs. treats her illness) through touch. Both FLs have a magical object hidden inside them that is the cause of their lack of magic or illness, and someone else is hunting the object.