Ah...I think acting irrationally upon anger or hurt isn't a very logical thing to do. You should take this into consideration before you assume that you have be a T to behave with cruelty.
Although I will admit that evil behavior is probably more associated with the two NFs that have tertiary T - INFJs and their sinister reputation, and ENFPs rage i.e. let me bulldoze you with my Te.
That is because you are NF. Plus the social norms are bult in a way that it is not likely that you will profit from hurting people. However thinking is vital part of it.
Of course there can be a scenario that the person will hurt someone because they hurt them first. (what is typical for NFs)
But to hurt someone deliberatly with an element of suprise and without remorse you will need alot of thinking. Since thinking allows you to see a person as a object that needs to me removed (or whatever).
By this I mean that you don't pay any attentiion at to their feelings and you don't care about their llife story at all. Plus you don't see how much damage you can do to people that love this person by harming him/her. Actually you see but you don't care since he/she is standing in your way.
While at the same time you don't expreiance anything on the inside since you are thinking and all your emotions come down to subjectivity of your own actions and they are nothing more at this moment.
Trust me thinking is a vital part of being a "bad person".
Of course there is a scenario that the person will hurt someone because they hurt them first. (what is typical for NFs)
That's it. This can be a big problem, if you don't recognize, that you hurt them. For example a NT can criticize an NF on a way, which appears harmless to NTs. But the NF feels attacked.
There was a situation on a seminar, where the seminar leader was ENFP. Every evening there was a possibility to ask questions about the subjects of the day. Sometimes the subjects were a little bit esoteric, and so some people (I assume NTs) ask about this. The leader reacted on a very cruel and bold way, attacking the questioner for this question personally. This happened in a room of 500 people.
NFs have very strong beliefs, and if the strong beliefs were questioned, the NF can react on this cruel way.
** Upgrading my english **
Corrections for my language are willingly seen
Cruel=as a defense mechanism in the short term, I cant see this in the long term being sustainable
evil=Yes. I think ENFPs make the best terrorists and martyrs. We can use Te in the short term for a defensive smack, but if you really, really offend our sense of (honor/integrity/justice/ideals), Te focuses on anniliation. We will destroy ourselves to destroy you.
I think we sense the inherent potential, so instead focus on endless forgiveness, compassion, and understanding. I work very hard to consciously choose to be forgiving and turn the other cheek, understanding the darker aspects that are the alternative.
The premise of this argument is flawed. Saying that NFs can't possibly be evil (or are only evil in a reactionary manner) negates the idea that "the exception proves the rule." The minority who are evil (if we can say that about someone) gives greater creedence to the ways of majority who are not. Besides, otherwise it makes it sound really self-righteous, like "Oh, aren't the NFs the greatest of humanity, incapable of hate or malice, beautifully benevolent in heart, truly the enlightened ones compared to the heathen that trudge about in the filth of their calculated logic and hedonistic desires."
A bad-natured NF is capable of a much greater evil on a larger scale than most all the other types. This potential is rarely ever realized, but when faced with convincing the masses that their idealology is correct, they'll succeed far and above what more thinker/action oriented types will be able to pull off. No one is going to jump on the cliched INTx bandwagon of evil-take-over-the-world scenarios because people don't like them enough and they rarely have the people skills to make it work. Take the NF understanding of people and flip the switch to evil and it's the recipe for mass genocide (Hitler seems to ring a bell).
Clearly, across the board, evil is the antithesis of the usual NF's mode of existence. But it seems a great potential for doing good can easily become a great potential for doing bad: they use all the same tools, just to a different end. A hammer can build a fence just as well as it can take it down.
I know an INFP. She's the most (emotionally) manipulative, sneaky, game-playing, defensive SOB I know. I think it's a pride/value-thing or an insecurity thing. Or maybe she just think it's fun. But she always ends up getting caught in her own web.
Example: She got involved with this guy who was though of as a "player". She knew this going in and she thought it would be fun and within "her rights" to play with him and his feelings. She felt like it was justified since he was familiar with the game and was doing "a bad thing". The more he liked her, the more she wanted to treat him bad, cause she ultimately wanted him to feel ditched, or something. However, she ended up falling for this guy and he stayed true to his nature. Maybe she wanted to change him, I have no idea.