Wakuna "The Chosen", also known as the "Lord of Guidance", is one of the legendary White Whistles in the Abyss, and is therefore presumed to have made outstanding discoveries down in the deep. He made his "Last Dive" to the 6th Layer some time before Riko's journey.
Wakuna appears as a man of imposing stature, and harbors a face hidden by a helmet with what seems to be a hole on its right side. His white whistle is shaped in the form of a whale.
He is also hinted to be quite old, since Bondrewd referred to him as "Old Man".
Practically nothing is known of Wakuna's personality. He certainly has a considerable amount of interest for the Abyss, considering his title of White Whistle and his epithet of "Lord of Guidance".
Wakuna has yet to make a proper appearance in the story. However, he has been mentioned a few times by his fellow White Whistle delvers, namely Ozen and Bondrewd.
Nothing is known of Wakuna's abilities, but it can be assumed that he is extremely competent. He invaded the incredibly dangerous sixth layer with "his personal relic", which presumes he possesses extraordinary offensive and defensive strength despite his advanced age.