I am an INTJ and a 5w6.
INTJs live in the world of ideas and strategic planning. They value intelligence, knowledge, and competence, and typically have high standards in these regards, which they continuously strive to fulfill. To a somewhat lesser extent, they have similar expectations of others.
The 5w6 is naturally introverted and second they have a rich intellectual world. A lot of 5w6s find learning, reading, writing, and researching more enjoyable than spending time with other people.