Hyde Kido (城戸 灰都 Kaido Haido) is the main protagonist of Under Night In-Birth series, he is presumably part of the Night Blade organization due to his partnership with Linne.
Straight-forward and strong-willed, Hyde is an individual who gives his all to any challenge before him and doesn't back down from a fight. Although normally cool-headed, he has a cocky and reckless side to him and tends to head into extremely dangerous situations without a second thought. Despite this, he is shown to be understanding the responsibility of his role as the Insulator's wielder, as well as being well-aware of his life being on the line. Hyde himself has stated that he has no desire for power and only wants to live his life like a normal person.
Hyde is someone who greatly values his friends and comrades. Although he is capable of using Insulator to kill Linne, he decides to postpone doing so as he feels that she has much more to teach him. He was also hesitant to fight Orie due to the positive relationship they have and offers Vatista a place to stay until she completes her mission.