Millian

Millian is the HET ship between Milah and Captain Hook from the Once Upon A Time fandom.

Canon
Milah first meets Killian in " devil's due" when a man knocks into her, spraying her drink over her blouse, which he amorously wipes off, with much protest from her. She is rescued by Killian, a pirate captain, who punches the drunk, and then kisses her hand with gentlemanly courtesy. Appealing to her sense of adventure, he describes the far away lands he's seen and invites her to join him. Milah declines, despite wanting to accept, because of her obligations to her husband and son. He accepts this, but he leaves the invitation open for the future, stating he's in port often. Later, Milah watches her son's condition continue to worsen, when Rumplestiltskin returns with the potion. She frets over needing to hide Fendrake's corpse, however, Rumplestiltskin explains the deal he made with the healer, in which he'll owe him his second-born child. Milah, horrified that he sold away their possible future, coldly thanks him for deciding her life, before storming out to the tavern.

Milah's marriage with Rumplestiltskin continues to deplete as she secretly keeps company with Killian and his crew at the local tavern, without her husband's knowledge. One day, Rumplestiltskin arrives to the tavern, beckoning her home. Milah initially refuses, but she relents after Baelfire begins calling for her. Later, while laying in bed, she expresses displeasure to Rumplestiltskin of her current life. Milah wishes to leave village life so they can explore and see the rest of the world. Oblivious to her concerns, Rumplestiltskin asks her to try to make their marriage work for their son's sake. She agrees reluctantly, but during the night, she leaves behind both her husband and son to join Killian on an adventure travelling the seas. By the next morning, word spreads that Milah has been kidnapped by Killian. Rumplestiltskin begs Killian to return his wife, but he is too afraid to fight the pirate and returns home alone. Ashamed of his own cowardice, Rumplestiltskin lies to Baelfire, telling him that his mother is dead. ("The Crocodile")

Years later, Milah interrupts a duel just as Rumplestiltskin, now the Dark One, is preparing to kill Killian. She clarifies that Killian never kidnapped her, and she went willingly with him due to their mutual love for each other. While Rumplestiltskin is seething over this, Milah holds out the red hat of his associate, Smee, and reveals she is possession of the magic bean he so desires. In exchange for the item, she wants Rumplestiltskin to leave her and Killian alone. To carry out the deal, Rumplestiltskin ascends onto the deck of Killian's ship and questions her about leaving their son behind. Milah retorts that she has lived with the regret of leaving Baelfire, but couldn't stay in a loveless marriage with Rumplestiltskin. At one point, he moves to grab the bean from her hand, but she throws it to Killian. When she claims to have never loved him, a furious Rumplestiltskin rips out her heart. Collapsing in Killian's arms, she proclaims her undying love for him just as Rumplestiltskin crushes the heart to ash, killing her instantly. ("The Crocodile")

After her death, Milah ends up in the Underworld, unable to move on because she harbors guilt over abandoning Baelfire. She assists Emma Swan and Rumplestiltskin in saving Killian from Hades' prison, but Milah is thrown into the river of lost souls by Rumplestiltskin and she is gone forever. ("Devil's Due")