Lon'qu. She knew his past already and got him to open up about it, curing his nightmares.
That's Panne, no? Or do they both help him with his nightmares?
In the Cherche + Lon'qu support we learn his backstory and why he's afraid of women: The village he lived in as a kid was raided by bandits and the girl he liked was killed trying to protect him. Her parents blamed him for her death, and the combination of being hated by her parents and the guilt of not being able to save her life made her afraid to speak to women. He says that she died because she was his friend, and so he won't let any women get close to him again. But Cherche reveals that her parents forgave him after learning how much he tried to protect her. Cherche knew him as a kid from her village and after talking to her his nightmares lessen.
I haven't read Lon'qu x Panne, so I don't know about that one.
Ahh. I only have Lon'qu x Panne at B right now but he tries to return a bag of herbs to Panne that she reluctantly takes from him. She uses the herbs to make a remedy that helps him with his nightmares, because she has nightmares as well of her warren being slaughtered.