Diane would probably be overjoyed. She's always been close to Meliodas and Elizabeth, and she would likely offer to protect them and help out in any way she can. Maybe she'd use her giant strength to build a special place for them to stay during the pregnancy.
Ban would probably be excited and start thinking about all the fun things he could teach the baby, like how to steal food without getting caught in a humorous way. King might be a bit more reserved at first but then offer to make the most beautiful crib with his powers. Diane would be super excited and offer to babysit all the time, cooing over how cute the baby will be.
I'm not sure specifically as there could be many novels named Tristan. It might be about a character named Tristan, perhaps his adventures, love stories or his personal growth journey.
Sadly, without further details, it's impossible to say who wrote the 'tristan novel'. It might be a relatively new author trying to make a name for themselves, or it could be an established writer's lesser - known work. It could also be a novel from a different country or culture, and the author might be someone who is only well - known in that particular region.
Yes, there are likely fanfictions out there with such a concept. Fanfiction writers often come up with creative and unexpected crossovers like this. You can search on popular fanfiction websites such as Archive of Our Own or FanFiction.net to find stories based on this idea.
Tristan was a knight, often sent on important missions. Isolde was a noblewoman. They became lovers because of a love potion, and their relationship was full of passion and secrecy in the context of Isolde being promised to King Mark.
The story of Tristan and Isolde is a tragic love story. Tristan was a knight sent to bring Isolde to marry his uncle, King Mark of Cornwall. But on the journey, they accidentally drank a love potion and fell deeply in love with each other. Their love was forbidden because of Isolde's betrothal to the king. They had to hide their feelings, which led to much pain and ultimately a tragic end.