One of the many ways this shows itself is the how INFJs are known as the most extroverted of the introverted functions while ENTPs are known as the most introverted of the extroverted functions, so the two are excellent at meeting each other half way and bouncing off of each other.

In Deku's case, his INFJ shows up strong in how formal he is around most people, even his closest friends, thanks to a mixture of anxiety and the desire the to please others and keep the peace, rather than risk the chaos & uncertainty that might come with revealing their overly emotional and passionate selves.

ENTPs, with their impish charm and sense of humor, have the uncanny ability to disarm INFJs completely. They are the INFJ's chill pill, excellent at making them at ease, safe to reveal all of their passion, their ideas, their personality. The ENTP's knack for chaos makes them appreciative of other people's uniqueness, which in turn makes them attracted to the basket of quirkiness that always come with INFJs.

That last scene of rddk laughing their asses off despite the world almost ending and the both of them casually bleeding from severe wounds is like the most INFJxENTP shit I've ever seen.

We've rarely, if ever, seen Deku treat such dramatic situations with such gaiety because while many people wouldn't, INFJs much less so. INFJs can be such serious, intense people with very set ideals of what's okay and what isn't. But with the ENTP at their side ready to crack the perfect joke at the perfect moment to break the tension, everything goes out the window and the INFJ realizes that things don't have to be so serious when actually they are quite fucking funny because what the hell. From the outside, it'd look as though the INFJ becomes a different person around the ENTP. In reality, that person has been there all along, but requires the right kind of energy to show themself.