Both are short length dramas with a modern day FL in a historical setting.
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Both dramas have a poisoned ML and a FL from another time who is the only one who can cure/ease his condition.

Both are historical setting with a long-term poisoned ML who can only be treated or cured by the FL. Both MLs are royal.

Both are short length dramas with VR elements in which a modern day FL enters a historical world and falls in love with the royal ML.

Both have a doctor FL from modern day in a historical setting. Both MLs are royal and have an illness (poisoned vs. medical condition) only the FL can cure. Both dramas are relatively to very short.

Both are short dramas with a modern day FL entering a fictional historical world and falling in love with the royal ML.

Both are shorter, fluffy dramas with a historical setting, and a poisoned ML. The FLs are able to cure/treat the ML.

Both have a modern day FL traveling to a historical setting with VR/game elements. Both MLs are royal, and much of the story is set in the palace.

Both dramas have a modern day FL in a historical setting with VR elements.
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Both dramas feature a modern day FL in historical times with VR elements. Both MLs are royal and both have palace settings.

Both dramas feature a modern day FL in historical times with VR elements. Both MLs are royal and devoted to the FL.

Both are short dramas with a modern day FL in historical times with VR elements. Both MLs are royal.