I don't have enough information to say exactly who Miu Sakamoto is in this context. They could be an author, a storyteller, or someone involved in creating this 'never ending story'.
The voice of a story in English usually refers to the style or tone in which the story is told. It could be serious, humorous, or something in between.
I'm sorry, I don't actually know the specific 'Nicolae Miu story'. There could be many people named Nicolae Miu and without more context it's hard to tell a particular story.
I would recommend 'The Adventures of Sherlock Holmes'. The stories are full of mystery and intrigue. The characters are vividly described, and the plot twists keep you hooked. The English voice for this, if you can find a good audiobook version, really brings the Victorian London setting to life.
The theme of adaptation is prominent. Iruma has to adapt to the completely different and often crazy rules and customs of the demon world. Also, there is a theme of defying expectations. Despite being a human in a world of demons, he manages to exceed the low expectations others initially have of him and rise to great heights.
Clara is an important character. She is a very energetic and somewhat unpredictable demon. She befriends Iruma early on and is always getting him into all sorts of strange and fun adventures. Then there is Sullivan, the demon who bought Iruma. He acts as Iruma's grandfather in the demon world and is very powerful and protective of Iruma.