Sometimes a character must die. Yes, even one we love.
Why? One reason only, really, and that is to promote the growth of another character. Just employing it as a ‘plot twist’ is not sufficient unless it serves such a goal. Well, that is unless it is a very minor character who does not impact much of anyone or anything in the story. Someone has to die in the battles, after all.
I have knocked off both primary and secondary characters on occasion. Hmm, the first? That would be Percos, brother of Perdos, in the first Donzalo’s Destiny book, ‘The Song of the Sword.’ It serves in all sorts of ways to thrust Perdos — a fairly minor actor to that point — into an important secondary role, first as a seeker of vengeance and then as a man who finds redemption.
In the next book in that series/novel, ‘The Hand of Asak,’ we have Donzalo’s true love kicking the bucket. Yes, it was always planned and was necessary to his development — and also to that of his primary antagonist, the sorcerer Lord Radal. It is the event that truly turns Radal into a man who wishes to destroy the young knight at any cost (including his own life and soul). The reasons for that, naturally, will not be spilled here.
Killing off the lover — I’ve done that elsewhere, too. It is a drastic measure, devastating to the lead character. Not to be overused! Only twice, so far, and no plans for more. Now, other primary characters and secondary characters can lose those they love, also, and that is certainly something that should occur. But be careful about using the device on your main protagonist — it can be a crutch, an easy way to change course.
People do die in real life and, therefor, in books. Fathers and mothers, lovers, friends. It would be unrealistic if no one ever passed on. But try to make the deaths serve a purpose. Even if they are seemingly random, they will impact others. They will change people. Our job is to explore how.