Functional Order: Te/Ni/Se/Fi
Dominant Function: Te
Thranduil proves himself a capable fighter, but intends to pull back once he realizes they can spend numerous lives without attaining anything. It takes him no time at all to muster a force and march it to the mountain within days of the dragon’s defeat. He tends toward rapid judgments and actions (banishing Tauriel, ordering his forces to attack). Thranduil refuses to come to the dwarves’ aid because it would risk too many elf lives in a profitless venture.
Auxilliary Function: Ni
His rigid views and perceptions are both an asset and a liability when it comes to reasoning with other people; once Thranduil forms an opinion, nothing shakes it. He expects negotiations to fail and has a clear vision of how he intends to handle it; his insights into what will happen are sometimes cuttingly accurate. He disregards others’ ideas and indulges them, with amusement. Thranduil sees the lost stones as a representation of the beauty, freedom, and power of his people, which is why he wants them. If he cannot see future success, he does not act. He is unafraid to engage the enemy, ride into battle, and even fight on the front lines.
Tertiary Function: Se
Once the dragon dies, he sees an opportunity to move in an army and demand “what is mine by right,” the lost stones of starlight which belong to his people. Thranduil trades a false promise of freedom for information, then murders the orc who carries it, in defiance of his word. He intends to use military force rather than negotiation to get what he wants, and sneers at Bilbo and the Bard’s ideas that they can “reason with dwarves.”
Inferior Function: Fi
He is willing to banish Tauriel from his kingdom for defying his orders. Legolas says that it’s clear Thranduil loved his wife, but he “never mentions nor remembers her.” It’s true, Thranduil cannot even bring himself to say “I love you” to his own son; instead, he reminds Legolas that his mother loved him more than anything, and urges him to find and befriend Strider. Thranduil refuses to accept Tauriel’s affections for “the dwarf” as true love until he sees her pain; it reminds him of his own loss, and makes it “real” in his mind (inferior Fi).
Note: The argument is taken from Funky Mbti in Fiction