I know a few authors who have said that their characters often come to life or evolve while they (the authors) are writing. I imagine that must be like a ‘Henry Frankenstein’ moment from the 1931 film, in which the dialogue goes:
“Henry Frankenstein: Look! It’s moving. It’s alive. It’s alive… It’s alive, it’s moving, it’s alive, it’s alive, it’s alive, it’s alive, IT’S ALIVE!
Victor Moritz: Henry – In the name of God!
Henry Frankenstein: Oh, in the name of God! Now I know what it feels like to be God!“
That ever-glorious god-complex. Not that I’m saying authors have a god-complex. Never.
I’m 5,000 words in (I know, I know, I’m moving slow) and one of my main characters is turning out to be a force to reckon with. When I was doing her characteristic profile she was supposed to be a little bit outspoken, passionate and fearless; but only more so than her male counterpart. However, in what I’ve written so far, she came across as all of those things multiplied ten, and that is a problem. There was supposed to be a level of insecurity in the character; enough to result in an addiction to a fictional drug, which essentially drives part of the overall theme.
Wait, does this mean the character came to life? It’s alive and I’m a god! Alright, no more stale jokes.
My characterisation* approach to this particular character was explicit and indirect , meaning some of her personality traits were revealed through another character’s perspective, and it was not in line with what I had in mind. Therefore, I’m going back to the drawing board. That is, if i can find the notebook where I did the characteristic profile for each character. Now I see why those notes are important.
Characterisation is a strategy  or literary device  utilised by an author to present particular information or details about a character. Some papers might refer to using ‘flat / 2-dimensional‘ versus ‘round / dynamic’ characterisation, or using ‘direct / explicit‘ versus ‘indirect / implicit‘ approaches to characterisation.
The Direct / Explicit approach to characterisation – in short – involves introducing a character from another character’s perspective .
The Indirect / Implicit approach to characterisation is a subtle way of describing a character’s traits. The reader has to discern these qualities through the character’s thoughts, actions, reactions, and interactions throughout the book .
Flat / 2-dimensional characters are uncomplicated, and they do not grow or change throughout the story. For example: Jane Austen used short sentences to describe Mrs. Bennet in Pride and Prejudice .
“She was a woman of mean understanding, little information, and uncertain temper. When she was discontented she fancied herself nervous. The business of her life was to get her daughters married; its solace was visiting and news.”
(Austen, 1813, p. 3) 
Round / dynamic characters have complex personalities, they go through change and growth, and they are usually the main characters such as Elizabeth Bennet in Pride and Prejudice .
They’re all equally effective in conveying whatever character-information the writer wants the reader to know, and can pop up at different points in fiction. The first two approaches – in my opinion – work exceptionally well with First Person and Third Person (omniscient and limited) narrative modes, particularly where the reader is always ‘inside’ of a character’s mind.
In school I was taught to use the British Standard of English, so if you’re from the US and you see words being spelt with the letter ‘S’ in place of a ‘Z’ etc., this is the reason why. It may interchange from time to time, but that is primarily due to the auto-correct setting on whatever USA-based software I’m using, and me not caring. Spelling is neither here nor there with me.