One of the things that seems glaringly obvious to me in the anime Berserk is that one of the main characters, Griffith, is a strong ENTJ. This means, in essence, that Griffith is extroverted, not introverted (that essentially he gets his energy from the external world, not his internal world), that he is an iNtuitive, not sensory, thinker (that he thinks more in generalities and abstracts than in specifics and facts), that he is a thinker, not a feeler (that he believes more in what’s "right" than what’s "fair", more in "facts" than in "feelings") and that he is judging, not perceiving (that he likes to plan things, rather than let things take their course).
What does this mean? ENTJs are known as the field marshals, and love taking far sighted, strategic goals and making them into reality. ENTJs have a need to impose control on their external worlds. They have to set goals and achieve them. They are natural leaders. They like logic and problem solving. They’re interested in many diverse things. They have tremendous energy. They deal well with people, but have a tendency to be aloof. They’re known to be too harsh, too critical, but also too complimentary. They’re cutthroat. The ENTJ quote is, "I’m sorry, but I have to kill you." ENTJs generally like people, but don’t specifically care about them, meaning that they might happily have a conversation with someone about something they like, and yet still be willing to lay them off if necessary for the profit of their business. ENTJs often get along superficially with almost anyone, but have more trouble when it comes to close personal relationships where they have to feel rather than merely think.
ENTJ’s greatest strength is also they’re greatest flaw. ENTJs are wonderful leaders and extraordinary visionaries. But they often have trouble relating to other people, particularly where feelings are concerned. An ENTJ might have an easy time understanding other people’s feelings (in order to lead or control them), but has a hard time understanding his or her own feelings. ENTJs don’t tend to like to feel. They want to remain cool, aloof, impartial. They don’t want to become irrational about people, to feel too strongly, to fall in love with someone "unsuitable", to become too close of friends with people who should be coworkers.
These can be good traits. Becoming friends with coworkers can mean that you pass up opportunities for advancement because you have to leave your friends or become their superior. Falling in love can mean settling down, again passing up possibilities for success. Marrying someone because you’re "in love" can lead to messy divorces and money problems. ENTJs are useful in many areas because they can detach themselves from people. They can lay people off as business leaders. They can solve problems involving multiple disputants without getting personally involved and taking sides. And as generals, they can lead men who they genuinely care about into battle, knowing that these same men will likely die on the battlefield. Being able to detach yourself from your emotions can be a good, healthy, and useful things.
Of course, these advantages do not mean that ENTJs always detach themselves from their emotions and never feel or do irrational things because of feelings. They do have irrational feelings, they just feel irrationally poorly because, without the ability to accept these feelings, ENTJs often can’t work at understanding and properly channeling them (for instance, saying, "I accept that I’ll marry this person even though they’re bad with money, but I’ll make sure that we make allowances for that and have me write the checks"). Because of this, it is considered relatively typical for an ENTJ to have feelings that are "unacceptable" to them about someone or something and to then act as if these feelings aren’t there. Of course, this only works for a little. Before long, the feelings do begin to escape, blown out of proportion or shifted into something dreadful. Even when these feelings are internally acknowledged, ENTJs often have a hard time telling other people how much they mean, personally, to that ENTJ.
Beginning to see a pattern? Griffith, as a strong ENTJ, does like people. He has to. In order for someone to like you, you generally have to like them in return. And Griffith is loved. However, he doesn’t really see himself as liking specific people in a personal manner. That would be to get too close, to step in the way of his goals. He doesn’t want to chance getting to like people too well. He likely avoids Caska at least in part because he does not want to get too close to her, to begin to like her as a person rather than as a coworker. Unfortunately, despite that Griffith does not want to personally like any of his comrades in the Hawks, he does begin to like Guts despite himself.
Of course, Griffith cannot admit this. To admit that he likes Guts would be to admit that he has feelings, that he has emotions. In episode 12, we watch Griffith claw into his own arms in order to maintain a calm enough demeanor that he can talk to Caska about selling himself into prostitution. If he’s willing to inflict physical pain on himself to avoid admitting that he, like all humans, has feelings, then he is more than willing to deny feelings. If he says that he only thinks of Guts as a valuable asset, that’s all Guts is, right?
But Griffith doesn’t really feel that Guts is just an asset, he has just decided that Guts is. Griffith feels that Guts is a friend, a confidant, someone whom he can talk to, someone whom he can care about, maybe even someone whom he can relate to. However he thinks that Guts is primarily a useful swordsman who can win battles for him and destroy his enemies. The thoughts and the feelings play against each other, but only the thoughts are accepted. Because of this, when Griffith describes to Charlotte the importance of his comrades, he calls them "not necessarily friends. They are valuable subordinates". To Griffith, acknowledging that Guts is his friend agrees with feeling, but does not agree with thought. As an ENTJ, Griffith goes with thought, and tries his best to ignore feeling. Guts is his "valuable subordinate", not his "friend".
Of course, feelings still rest inside Griffith, buried only under a thin layer of logic that has attempted to hide them away, but cannot deal with them or fully suppress them. They emerge, as might be expected, at times of high stress. This is why, when Guts tries to leave Griffith, that Griffith becomes so upset. He feels that Guts is his friend, therefore Guts leaving him is not just an impersonal choice for Guts to find another opportunity elsewhere, but rather a choice to abandon Griffith personally.
Griffith likely does believe that feeling that Guts is leaving him, and him personally, is irrational. But this does not stop him from feeling that he is being personally rejected. Griffith is upset. Irrationally so. And likely Griffith is made to feel even more upset by the fact that he knows that he shouldn’t be feeling so upset about Guts leaving him.
Another gift that can be a flaw of ENTJs is that they have a lot of energy. They always have to be doing things. And most of them have trouble realizing that "doing nothing" is "doing something". A well developed ENTJ can realize that, in a time of crisis, sometimes the best thing to do is to wait for a good opportunity and take that opportunity, or just let things go. But the more stressed an ENTJ becomes, the less able they are to wait. The more stressed an ENTJ is, the more they are forced by their personality to take any action, no matter how pointless, no matter how bad, as it presents itself.
Griffith, unfortunately, falls prey to his personality type again. When Guts leaves, he could (and should) ask him to remain and, when Guts refuses, say that he was glad to have had him and that, should Guts ever wish to return, that the Hawks would love to have him again. But Griffith cannot do this. He is both personally, and irrationally, hurt by Guts "abandoning" him. And he cannot stand the idea of inaction. The action that presents itself is to challenge Guts to a duel. And so Griffith takes it.
Yet another trait NTs (ENTJs and INTJs in particular) have is that they are very competitive. I have heard kind, gentle NFs (think Charlotte) say about NTs that "they won’t respect you until you beat them". This is somewhat to completely true. Similarly, NTs will not respect themselves until they’ve won, and feel that other people lose respect for them when they lose (this is more true for ENTJs than any other NT in that, being extroverts, they actually do care about other people’s opinions, unlike INTJs who care, but care considerably less).
What does this mean? It means that
when Griffith challenges Guts to a duel, he needs to win. He needs to win
to prove that he’s still in control. He needs to win to prove to the Hawks
that he is still the one in power. And he needs to win in order to
"control" Guts and to bring him back to being his "friend" or "associate",
a role Griffith needs him to have (poor Griffith doesn’t appear to have
made many friends! And yes, ENTJs are known for trying to control
everyone and everything, including people who should not be controlled
like friends.). This means that Griffith intends to win, even if
it does mean that Guts may have to die if Griffith makes a mistake.
The combination of being "abandoned" by
his only "friend", losing, and just knowing how upset he is by both of
the above is very stressful to Griffith. To him, he has just lost control
and competence, the two key qualities ENTJs care for. He has also
lost an emotional support and doesn’t know how to manage his feelings.
Needless to say, this is a blow to Griffith, one which tears him up and causes him tremendous pain. It is one that he should be able to get over, given time. But Griffith, again, is driven by action, not inaction. And because of that, this blow is one that drives the remainder of the series.