Functional Order: Ni-Te-Fi-Se
Tom was an extraordinarily gifted student at Hogwarts, but started crafting an ideal for his future from a very young age, in his desire to defeat death through using a dangerous dark magic known as Horcruxes—the splitting of his soul into “objects.” Rather than the typical one or two, however, he wanted to know if one could split it into 7 different forms, and sought to imbibe his living self into different objects of personal significance and symbolism, such as the objects that represented the Hogwarts Founders and his own family heritage. He sought the Dark Arts position, at least under a pretext (that he might gain access to these valuable items), for many years, but also had a sense of forewarning that Dumbledore was suspicious of him, which made him change course. Tom is both a long-term planner, such as when he gave Lucius Malfoy his diary to protect, and impulsive under stress—when his wand fails to destroy Harry and even implodes in his hand during the chase when Harry tries to escape, he sets out to take the Elder Wand, not pausing to deeply learn about wand lore or question Snape about what happened on the astronomy tower, or when he murders Lily Potter to get at her son, which turns Snape against him. He is efficient in what he does, in establishing a following and an order, but also in his willingness to do whatever it takes to ensure his own survival… with the result being that Voldemort can isolate, terrorize, and even kill his own followers in his blind rages. Because of his antisocial tendencies and the characteristics he has of a psychopath, he neither understands nor appreciates human affection and love, which causes him to devalue Snape’s attachment to Lily. It’s in the way of his survival, which he takes through the most direct means possible—a prophecy foretells his downfall at the hands of a boy, so Voldemort decides to kill him long before he can become a man. The woman matters “not” to him, so he thinks nothing of her death, and fails to realize how much she meant to “his most loyal servant.” His own contempt for his Muggle father leads him to push away from his family and reinvent himself.
Enneagram: 3w4 sp/so 
Tom Riddle became “Voldemort.” The Half-Blood adopted a Pureblood stance, against Muggles and their offspring, against Squibs, against anything beneath him, in his quest for absolute power, and for, above all, “glory.” He wanted to become notorious, remembered, the most powerful wizard in the world—and chafed when Harry, in the Chamber, reminded him that position belongs to Albus Dumbledore. He was cold, callous, and arrogant at school, full of himself. He chooses impressive objects in which to house his soul, because of his arrogance – few things are good enough for Lord Voldemort, but relics of the Founders of Hogwarts might just do. Harry knows that he would not choose just “any old cup.” He also is temperamental, even childish in his tantrums, emotional at times, elitist in his need to be superior to everyone else, and inclined to drive people away from him – he taunts and belittles and maligns and humiliates his followers, to stroke his own ego, defeating himself in the process.