暗黑冰河（Black Swan）是《聖鬥士星矢》原作中登場的角色之一，隸屬於「暗黑聖鬥士」勢力，擁有與天鵝座冰河相對應的黑暗版本聖衣。主要出現在「暗黑聖鬥士篇」中，作為鳳凰座一輝的部下。與其他暗黑聖鬥士一樣，由一輝召集並在死亡皇后島訓練的邪惡戰士。

來自芬蘭的他，象徵著「光明的天鵝座冰河」的反面，代表著黑暗與冷酷。暗黑冰河與冰河之間的關係，不僅僅是力量上的對抗，更象徵著兩種價值觀的碰撞—正義與邪惡、冷靜與殘酷。

在外型設計上，暗黑冰河的聖衣與天鵝座聖衣極為相似，但顏色主要以黑色與深灰色為主，象徵著黑暗的力量。他擁有冷峻的外貌和沉著的性格，與冰河的堅定和剛毅形成鮮明對比。戰鬥風格與冰河極為相似，擅長操控冰系小宇宙進行攻擊。雖然他的實力比不上真正的天鵝座冰河，但他的招式在黑暗小宇宙的加持下，依然能夠發揮強大的威力。

必殺技是暗黑暴風雪（Black Blizzard），針對冰河「鑽石星塵拳」（Diamond Dust）的模仿與扭曲版本。施展時，會釋放出黑暗的冰霜，形成大量細碎的黑色冰晶，宛如鑽石般散發出冰冷的黑光。與冰河的鑽石星辰拳不同的是，他的攻擊中蘊含黑暗小宇宙，擊中敵人時不僅會造成冰凍傷害，還會侵蝕對方的小宇宙，使其感受到一股來自黑暗的壓迫感。雖然招式威力不及真正的鑽石星辰拳，但在短時間內仍能對對手造成不小的威脅。在戰鬥中，常利用這技能對冰河進行牽制，希望藉此擾亂對方的節奏，進而削弱天鵝座聖鬥士的力量。

最主要的登場劇情為「暗黑聖鬥士篇」，這段劇情發生於銀河戰爭之後，當時鳳凰座一輝為奪取女神雅典娜的聖衣碎片，率領暗黑聖鬥士襲擊星矢等人。在戰鬥中，與天鵝座冰河展開激烈交鋒。兩人的戰鬥被描繪為光明與黑暗的對決，暗黑冰河企圖利用黑暗鑽石星辰拳凍結冰河的小宇宙，但最終仍然不敵冰河正義且純粹的力量。在戰鬥的最後，冰河釋放出更為強大的鑽石星辰拳，徹底粉碎暗黑冰河的攻勢，將其打敗。

這場戰鬥不僅彰顯冰河作為正義聖鬥士的強大實力，也象徵著光明戰勝黑暗的寓意，強化主角群聖鬥士們對抗邪惡的信念。他的存在，除了作為冰河的對手之外，還象徵著「鏡像對立」的概念。在《聖鬥士星矢》中，暗黑聖鬥士常被視為主角群的黑暗映照，這不僅強調主角們面臨的挑戰，也展現每位聖鬥士內心可能存在的陰影面。

冰河之所以能夠擊敗暗黑冰河，正是因為他在戰鬥中堅守內心的信念與正義，無懼黑暗的侵蝕。這也呼應整個《聖鬥士星矢》系列的核心主題：「真正的力量來自堅持正義與守護他人之心」。雖然在劇情中登場時間不長，最終也在與冰河的戰鬥中敗北，但他的角色形象與象徵意義，仍為作品增添更多層次與看點，成為《聖鬥士星矢》暗黑聖鬥士篇中不可忽視的一環。

Black Swan is a character from the original Saint Seiya series, belonging to the faction of Dark Saints. He possesses a dark counterpart to the Cygnus Cloth worn by Hyōga and primarily appears during the Dark Saints Arc as one of Phoenix Ikki’s subordinates. Like the other Dark Saints, he was recruited and trained by Ikki on Death Queen Island, becoming a malevolent warrior.

Hailing from Finland, Black Swan symbolizes the opposite of the "radiant Cygnus Hyōga," representing darkness and cold ruthlessness. The dynamic between Black Swan and Hyōga transcends mere physical confrontation, embodying a clash of ideals – justice versus evil, calmness versus cruelty.

In terms of design, Black Swan’s Cloth closely resembles Cygnus Hyōga’s but is predominantly black and dark gray, signifying the power of darkness. His stern appearance and composed demeanor contrast sharply with Hyōga’s resolute and steadfast nature. Black Swan’s combat style mirrors Hyōga’s, specializing in ice-based Cosmo attacks. Although his power does not match that of the real Cygnus Saint, his techniques, amplified by dark Cosmo, can still unleash considerable destructive force.

His signature move is Black Blizzard, a distorted imitation of Hyōga’s Diamond Dust. When executed, it releases dark frost, forming countless black ice crystals that emit a cold, diamond-like gleam. Unlike Diamond Dust, Black Blizzard carries the essence of dark Cosmo, freezing enemies while also corroding their Cosmo, instilling an oppressive sense of dread. Although less potent than the authentic Diamond Dust, Black Blizzard can pose a significant threat in the short term. Black Swan frequently uses this technique to disrupt Hyōga’s rhythm, aiming to weaken the Cygnus Saint's strength during battle.

Black Swan's primary storyline takes place during the Dark Saints Arc, following the Galactic Wars. In this arc, Phoenix Ikki leads the Dark Saints in an attack against Seiya and his companions, seeking to claim Athena’s Gold Cloth fragments. Black Swan engages in a fierce battle with Cygnus Hyōga, a fight depicted as a symbolic clash between light and darkness. Black Swan attempts to freeze Hyōga’s Cosmo using his dark version of Diamond Dust but ultimately falls to Hyōga’s righteous and pure power. In the climactic moment, Hyōga unleashes a stronger Diamond Dust, shattering Black Swan’s offensive and defeating him.

This battle not only highlights Hyōga’s strength as a Saint of Justice but also reinforces the theme of light triumphing over darkness, underscoring the protagonists' unwavering resolve to fight evil.

Beyond serving as Hyōga’s adversary, Black Swan embodies the concept of "mirror opposition." In Saint Seiya, Dark Saints are often portrayed as the dark reflections of the main characters, emphasizing the challenges they face and the shadows that may exist within their hearts. Hyōga’s victory over Black Swan signifies his ability to uphold his beliefs and justice, resisting the encroachment of darkness.

This mirrors the overarching theme of Saint Seiya – "True strength comes from upholding justice and protecting others." Although Black Swan's screen time is brief, and he ultimately falls in battle, his presence and symbolism add depth to the narrative, making him a memorable element of the Dark Saints Arc and an integral part of the Saint Seiya mythos.