Remus Lupin x Nymphadora Tonks
Even though she had long been familiar with the identity of her famous cousin and his friend, Nymphadora Tonks' first reaction when she walked into the dining room of No. 12 Grimmauld Place for the first time and saw the two middle-aged wizards sitting at the end of the long table was:
One is a werewolf and the other looks like a vampire.
The title is obviously a tribute to Lin Qinnan: The Legacy of La Traviata in Paris
Intention: one party saves the other party, one party guides the other party