There’s a lot of specific INFJ and some specific INFP stuff in their respective tags, but, okay. Let’s talk about anger.
Sure, why not.
Think of a time when you’ve been utterly furious. Are you:
a) The Hulk. You try and try to avoid conflict, but things build up and sometimes explode. The trigger is the initial focus, but really your anger is very unfocused and everything that’s been even remotely irritating ever is all coming out at once. No one emerges unscathed. Eventually it burns itself out and you limp away, assess damage and feel guilty. Even if you had the moral high-ground when you started, it is gone, gone, gone.
b) A sniper. Precise, targeted, patient and deadly. Your plans are long-term and exact (planning is half the fun – we know because you can be heard cackling madly to yourself). You feel really satisfied by enacting justice and destroying your enemies. You’re still mad years later.
INFP is a) Fi anger, INFJ is b) Ni anger. If you make an INFP angry enough to blow up, you will definitely know. If you’ve made an INFJ angry enough to plot revenge, you will probably continue to do so without knowing or caring. Eventually, though… eventually you’ll regret it.