In my novel, my character is at first cowardly, kind polite and saintly. but now I want to give him a more robust nature - ruthless and brave , due to an accident that he met with. How do I bring it about? Announcing it blandly to the reader or in a hidden manner, letting the leader find out for himself ?
I have done something similar with one of my characters and the change for mine came at the end. A turning point in his life. You can show this change through his actions and how his body language has changed. How he interacts with the other characters that is different to how he used to act and how they react to him.
Good luck
It's not wise to step out of character, or change the make up of a character mid-stream. The reader may not take kindly to a sudden change of character, from the one he o she has grown to know and care about.
You've got to clearly show the change/transformation, announcing it like that is a bad idea in my opinion. Perhaps you could have an incident/subplot to display the change, where the character would do the opposite to the obvious reaction he/she would have displayed earlier on.
Well, good luck.