Scope
The motivation behind building Immortals
It's a setting for my main characters, the immortals Fabia, Artur, Faruq, Geneviève, Matas, Katherine, and Helena. I have too much fun inventing names and details for worlds to keep the Earth of the immortals too similar to ours. Even if I mainly end up changing names, because I want to the broad strokes of history to remain, not tweaking feels boring.
The goal of the project
To provide a setting for the seven main people I'm interested in: the immortal time travellers in Europe. It's hard to have character interactions without having a context or anything but each other for them to interact with. Besides, it's a good excuse to research random bits of history.
Immortals's Unique Selling point
It's not unique - I cheerfully nabbed this idea from Guy Gavriel Kay as I'm a great admirer of his work. He doesn't have immortals who get flung through time or space, but the immortals themselves were absolutely inspired by The Old Guard.
Theme
Genre
Alternate historical fantasy, although the only magic appears to be that steering the journey of the immortals.
Reader Tone
Melancholy, but hopeful. Rather than looking at the sweep of history, a focus on the small details and the people that fill it. A dizzying diversity and yet how those are connected to basic human needs and desires. It's about finding all the small candles and lanterns that bring light and warmth despite the people who might try to put them out.
It can be hard and difficult going, but that doesn't mean it isn't worth it. An action doesn't need to change the whole world in order to be worth it. You can't fix everything and some things can't be fixed, but it's important to bring help and love where you can.