A distant ancestor of Captain Harlock and author of the book "My Youth in Arcadia," which chronicled his adventures as an aerial explorer. The one we see recalled in the Arcadia feature shows Phantom F. Harlock en route to Rabaul, New Guinea, by way of the Owen-Stanley mountain range. At first unable to crest the tall peaks, he mounts a second attempt when he seems to hear the mountains laughing at his failure. Jettisoning all excess fuel, leaving only enough for ten minutes' more flight time, he trusts his fate to the lightened plane, which he loves as his own flesh and blood, and nearing the tallest peak he sees a ghostly apparition of a woman's face: the Owen-Stanley Witch.
Many people have interpreted this sequence to say that Phantom dies in the attempt, though this is at odds with all logic, as he clearly survived to write of this exploit in his book. The "Witch" incident and the necessary lightening of the Arcadia's load are paralleled by the future Captain Harlock's travails in the Flame Stream Prominence, in one of the film's most clearly expressionistic story points: note that Phantom F.'s biplane changes color during the opening sequence, a color change mimicked by the battleship Arcadia in later times.
(Source: cornponeflicks.org/harlock/friends.html)