Chlammy Zell

Kurami Zell, クラミー・ツェル

A person who joined forces with the Elves to win a competition among kings because they believed that humans could not succeed on their own and needed to rely on others to survive. They were born into an influential family in Elven Gard, where they served as Feil Nilvalens' servant. Despite being forbidden from doing so, Feil and Chlammy developed a close friendship, which they kept hidden.

Spoilers:

She got into the final round of the contest by cheating with the help of Elf magic, but lost to Sora and Shiro, who used her schemes against her. When Sora yelled at her for underestimating humans, she threw away her confident façade and broke down in tears while childishly calling Sora names. In the third light novel, she returns to challenge the siblings, only to lose again, as well as losing all of her memories to them. In the end, Sora chooses to share his and her memories between them, allowing her to recover her own memory, as well as having Sora's memory. She is astonished at Sora's past. Believing that Sora will fulfill his words to unite all races, she now assists Feel in claiming the leadership of Elves.