WARNING: SPOILERS AHEAD!!
Some of you who have read "The Young Foreigner" must be wondering where I got such imagination from. I know my mother and my friends do, because they ask me such questions. It makes me happy when they do that, because I can clear see that they're amazed and would love to know how I'm able to create such a deep and complex world with equally complex characters.
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So, I thought I should consider where I got all my ideas from. Before we get into that, please refrain from thinking that the entire series is a fanfiction. Not that I hate that genre, but I just don't like the idea of writing one myself. I might occasionally read one written by somebody else, but I can't write by myself.
Now that's clear, let's tackle the actual question.
So, "The Young Foreigner", and eventually the rest of the series, was strongly based on "Once Upon A Time" and "Fairy Tail". When I say this, I repeat, this is not a fanfiction or a crossover. It's just that I've taken the different manners of looking at the age-old and well-loved fairy tales and the concepts of magical abilities from these two TV shows. I admit that some of the villains do run parallel to some of them, but overall, the story and its ideas are mine alone.
The others in the list include Egyptian and Greek myths (the one with Chaos/Apophis and the Oracle), English legends (Merlin), random anime shows (Elmeida's name was derived from a villain in "Kiba"; Seilah from a villain in "Fairy Tail"), "The Chronicles of Narnia" (the talking horses and the unusual swearing), Roman History (the concept of Seers), and I think the list goes on.
Yet, there are a few that need special mention.
The entire world-building was inspired by J R R Tolkein's "The Lord of the Rings". He created myths and legends and countries of his own and that is something all world-builders need to look up to. Even if you, as a high fantasy writer, do not like the books, there is something mesmerising in the whole story - something to take away from. I also made a map of Sahara, which I believe I haven't shared here with you. It's just as well, because it's all pencil-drawn and not at all worth seeing, until I get someone to recreate it in a better and clearer manner.
Also, the concepts that I've drawn from well-known fairy tales are just ideas. I've simply moulded them to best suit my story. Hence, any variations to the actual stories cannot be comparable to this one. Then again, the very stories I speak of have variants of their own.
The idea of Merlin's staff was my own. For some reason, I like staffs as sources of magical power and so, wanted to incorporate that somewhere. It eventually became Merlin's.
The telepathic connection is not necessarily derived from anywhere. It's just been in my head after too long a time of reading pure and high fantasy.
The entire story revolves around the idea of how Light and Darkness cannot exist without one-another. If one is present, so is the other. They're two sides of the same coin---they cannot be separated. Nonetheless, the concept of a person possessing/tethering Darkness and hence being able to sense fear was largely an idea inspired by the "Green Lantern" movie. Also, I'd always been of the belief that love is eternal and that it could never get old, if it's true. If it's true, then love cannot be judged based on the age of two people. It can happen any time and with anyone. These are the themes in which I mostly base my stories.
Lastly, the stories of Enid Blyton have always inspired my writing in general. The universal/third person style of narration has always fascinated me and I realise now that it has become unknown in the present century. That is rather sad, because I hold Enid Blyton in very high regard - in fact, her stories were among the very first I'd ever read when I was a little girl.
So there is the question answered.