ENTJ + INTP
ENTJ INTP relationship
Relationships between two NTs can be intense. This is especially the case with ENTJs and INTPs. Almost always this relationship ends up changing the two persons involved tremendously, usually for the better (this is IF they open up to each other enough).
Both ENTJs and INTPs are usually very bright, individualistic people and excellent debaters(although the INTP may not be as verbally/vocally fluent as the ENTJ). They are also both very often opinionated and don't back down or give in if they think they're right. Another thing to mention is however similar at their NT rational core they may seem, they look at the world from different angles usually.
What does this result in?
Debates! Lots of them! Which for an NT isn't all that bad as it seems. In fact, it can be damn fun and exhilarating (especially for the ENTJ). The fact that they think and observe things from different angles can bring them both insight they would never get on their own because one's blind-spot is the other's strength.
Of course, the relationship can be fun too, relaxing even, but you WILL have debates and arguments and that will usually be fruitful if debated with a goal of better understanding of something.
Unhealthy ENTJ INTP clash
However,if two "unhealthy" people of these types clash, it can turn into an outsmarting contest with piercing sarcastic comments that hurt more than an insult. The INTP suddenly starts looking unrealistic and disconnected from all reality to the ENTJ, and the ENTJ appears selfish, egotistic and downright evil to the INTP. The funniest thing amidst those "insults" is that neither will ever show they're hurt even the slightest bit because both are masters of hiding their feelings. If this happens, ask yourself, where am I going with this? Start doubting yourself first and realize that winning an argument for the sake of winning is just an ego trip that won't bring you much. Be human first and act with respect.
A few additional words
I'm sorry if this text seems a bit incoherent (I don't have the patience to structure it well now) but I hope it helps you to see the perspective of an ENTJ who's had her share of contact with INTPs and who respects them even though she sometimes hates their guts. I'm pretty certain that as they grow older INTPs and ENTJs get along better and better.
Also, here's another perspective on the ENTJ INTP relationship.