Requested by starsepphira
Note: This is based off of research & clips for primary sources
Personality Type: ENFP
Dominate Function: Extroverted Intuition
Mello is extremely smart and creative. He sees patterns and how they connect in the world around him. Mello tends to chase down different leads, and ally himself with a verity of people in order to hunt down Kira. He sees possibilities of who, where, and what is going on, rather than the uncanny introverted intuition sense of understanding double meanings and projecting what will happen next. He is expressive and tends to surround himself with people, despite his selfish goals and his frustration with others. Although he tends to intentionally alienate people, Mello thrives on stimuli to keep him motivated and inspired.
Auxiliary Function: Introverted Feeling
Mello makes his choices based on an internal, abstract set of criteria and values. He glorifies L in his mind, and tries to emulate him in his detective work. He fancies himself the best detective in the world, and works extremely hard to earn the reputation he feels like he deserves. His emotions often get in the way of his ability to project what is going to happen next, or thoroughly think through his plans. Mello is extremely intelligent, but opposed to the cold calculations of Near, Mello has a fiery, passionate personality that drives him on his detective work through brute force.
Tertiary Function: Extroverted Thinking
This is a less developed function for Mello, but he often uses it to set up traps and organize his plans. Mello is quick to give orders and move pawns around to where they need to be. He orchestrates traps or plans in order to get his hands on the Death Note and find Kira. Although he is excellent at organizing the world around him to suit his needs, Mello is prone to letting his emotions get in the way and foil his own plans.
Inferior Function: Introverted Sensing
Mello draws data from his past and memories to use in his plans and intuition. He knows how things have been done before with L, and wants to do similar kinds of detective work. He uses the past as as starting point to start brainstorming and strategizing. He even picks up the similar habit of eating sweets as L.
Hogwarts House: Slytherin
Mello is extremely up front about wanting to be the very best detective, and is constantly competing with Near for being the top strategist. His ambition and drive makes up for the fact that he is less apt about seeing how everything ties together than Near or Kira. It is his force of personality and need to be great that leads him to achieve many things and make the discovery he was searching for before his ultimate downfall.