Harry Potter, J.K. Rowling
Dominant Ti: Luna Lovegood’s logic comes primarily from what she personally thinks is logical and her beliefs do not change when other people point out visible or external evidence that counters her beliefs. She doesn’t talk much and when she does, she tends to stick to brief words. Luna never overreacts to anything and her emotions are generally rather tranquil. They don’t affect her decisions at all, and she relies on logic to build her worldview and solve problems. She’s very curious and loves to learn about pretty much anything and everything.
Auxiliary Ne: Luna believes pretty much anything is possible and is capable of finding links between pretty much anything. This is useful to Harry when it comes down to looking for horcruxes in Hogwarts. She’s good at recognizing ties between people and reading between the lines to know things she probably shouldn’t. She sees potential in everyone and often tells them about it to encourage them when they’re down. She wants to talk about all manner of ideas and theories (though she tends to accept all theory as truth). She can usually guess what’s going to happen next.
Tertiary Si: Luna isn’t particularly fixated on the past, but she does use her personal experiences quite a bit to give advice to and relate to other people. She retains a large store of seemingly random information that she’s gathered over time and uses it to help Harry find solutions. She likes to revisit things that have given her joy in the past, no matter how weird other people think they are.
Inferior Fe: Luna has a strong desire to help other people and does everything she can to be a kind friend to those who will accept it. When it comes to those who think she’s strange, Luna doesn’t get particularly offend and knows when to give people their space. She can read people’s emotions, but is so detached from her own emotions that she ends up painting pictures of them in her room instead of confiding in them.