Yeah... I might give the verbal knife caught on the spot. I've shouted at a guy grasping at my breasts: "Hey, you're old and fat and stupid, I can see why no woman would ever let you touch her out of free will, how pathetic it is to see, nobody will ever want you, you know that, so look, the harbour is right here, go jump in! Jump, you're an ugly old fart, come on now, people so sad and unwanted have no reason to live, you know that, and no one will miss you, it's over, you'll never get sex ever again, now go jump in already you sad little man or don't you even dare do that, impotent sissy!"
Then he started hitting me until my BF came rushing and diverted the violence.

)
I'm happy he didn't jump, we were standing at the edge of the harbour, next to his boat. But I never regretted a word. Boundaries, yeah, albeit a bit black&white in execution...

I was 18 at the time.
If I still have a small emotional opening, thus still *hope* that we can reach eachother I might care to show that I feel angry, offended or something. But if I've given up hope that the other party will understand or be able to respond constructively to such a show of feelings, I will not even bother to insult them with destroying observations. They have turned into an obstacle and I don't express feelings to obstacles. I remove them. So at some point I decide that communication doesn't further the goal I want to reach, and then even sharp, hurting comments is deemed a waste of energy and not worth the effort.
To me, Te in the service of hurt Fi can be a killer mode. Ice-queen is a good description, Amar. I'm going in to kills something, a connection and thereby a net of potentiality. That's sacrilege for an ENFP, so something dies inside yourself too. Yes, Fi approves that it's necessary in order to keep something more important alive, but still. You die a little, it leaves you somewhat empty and exhausted. I'd mostly rather avoid it.
But I think the killermode - accepting to kill a network of potential in order to finish some imperfect actuality - could be put to good use at completing tasks at work. If only I could get it activiated without the emotional hurt and anger triggering it ...