So after a lot of thought lately I not really finding an appropriate answer I have a very complex question to ask. How would a character react to watching a loved one die and being able to nothing about it. I have read a range of answers from out right breaking down immediately to not reacting at all and both seem like the extreme ends of opposite spectrums. The best I can come up with is some sort of shock but I am not really sure what this would entail. Would the character sit there stunned and unable to react due to an overflow of emotions or would something else entirely take place. That and I have to imagine that when placed in a situation where the characters life is also in peril may change the reaction as well.
There isn't a single answer to this, because grief, shock, anger and frustration are all components of possible reactions and each person reacts in his or her own way. I think you know the range of reactions; what you seem to be struggling with is which one is the right one for your character, and we can't answer that because no one knows your character like you do. Get inside your character's head. Get to know him/her as well as you can, then put yourself in his/her position and see what emotional response you get.
Your choice will be a reflection of the character, but it need not be direct. People react in strange ways to extreme emotional stimuli, often surprising, or even frightening, themselves. One person may begin laughing uncontrollably. Another might feel an irrational relief, and then feel guilt-ridden and withdrawn. Some become the pillar of strength, taking comfort in helping others deal. You shouldn't be asking others how your character should react, unless you want boring, predictable characters. Tap into your own experiences with grief from the loss of a loved one. If you lack such experience, speak to others who have, but know that you will probably not get reliable information. As I hinted at, many people will feel ashamed of how they reacted, and censor it, perhaps not even admitting it to themselves.
I would try to put yourself in that position. Haven't you ever felt helpless before? Try to feel, in some way, how this character feels. That's your reaction.
One useful technique (just one of the many available to you) is avoidance. When we are confronted by something that is emotionally overwhelming, sometimes we take refuge in things that feel safe and routine to us. In the context of seeing someone you care about die, it comes across as bizarre and inappropriate, and it is likely to offend other people present. But it also speaks to deep-seated emotional pain and when used effectively, it can create a weird tension in the scene and provide hints as to just how much emotional pain the character is in. Again, it is just one approach (and not necessarily the best one for your character), but in the right situation with the right character, it can work.
anger, frustration, angst, guilt are all stereotypical reactions of a character in such a situation. They'll probably be physically agitated as well, as a result of shock (tightening the body, losing control of breath, hyperventilation, weakness, trembling.. the works). They'll probably try to think of a way to prevent the situation, but their mental turmoil might not allow reason. It is tantalizing for a writer to get into such a character's head, because it gives so much scope for expression. How your character reacts to this situation perhaps dictates their nature or rather, their nature dictates it. So in the end of the day, it is a matter of your requirements from the character. Hope this helped. Happy Writing
When you are upset, do you immediately start crying or do you let the frustration/anger/pain build for awhile before it comes out? Watching a loved one die would work similarly but on a much greater scale. It depends on the person's personality - do they easily admit defeat or would they be more likely to try and fight it? The first personality might break down right away, while the second one might be more likely to experience more shock, anger, and denial before the actual sadness comes. Also, try not to make it too extreme... I know your question is about immediately after the death, but I am now going to talk about later... don't overdo it. Unless it is a particularly unstable character, don't have them totally melt down and withdraw from society and be unreasonably depressed for a super long time. I have a friend who watched her mother die very recently and while she is obviously still very sad and will be for a very long time, she can still at least fake being unaffected and is still capable of laughter and smiles.
Stunned disbelief would be one of the first things a character would feel. In my MC's past, they were feet from freedom and her lover dies to give her a chance to escape, and instead she just STOPS. The shock of seeing what happened, and knowing he'd left her, became to much to move until too late, and it allowed her to die also. But disbelief, anger, depression, guilt, shock, all of those are fairly common reactions to tragedies.
If everyone were to react to a situation the same way, there would be little need to write it. The fact that people do react differently, and sometimes very differently, is what makes it worth revealing. Unexpected reactions tell the reader something special about your character. It's also where personal experience can really shine through. If your own experiences provide you insight into the range of reactions possible to some kinds of situations, a nugget of truth may well land on your writing, and your readers will sense that.
It all depends on your character dude. You can make him a heartless bastard who laughs at the death of his beloved, or he gets so pissed off, he murders the guy who killed his girl friend. Everybody has your own sense of emotion.
What ever the reaction best stay away from the "Nooooooooooooo!" angle Bur seriously I like the idea of not reacting at all at first and building his emotions up through out the story leaving us to wonder when he eventually will, like having unsettled dreams, mumbling, far away stares etc. Then when something hardly noticeable happens he goes either to pieces or flies into a fit of rage.