wiege is a song meant to bring comfort, a lullaby to, as the name suggests, lull someone into slumber. hyuna sings to luka to assure him he is still alive, to act as his counting of fingers personified, and vice versa, to calm hyuna when everything crashed on her, both metaphorically and literally. it's not a duet because the two singers are lovers. it's a duet because it symbolizes mutual solace between two kindred souls.
and so, the reason that ivan sings it alone, atleast in my interpretation, is because he always had to comfort himself, yet not always because he was lonely.
in the slums, who could've possibly given him sympathy? afterall, those children were truly, in the whole meaning of the word, alone, with no one to care for them in such a way. maybe the only thing he had left was to hum mindlessly, maybe in the same way luka counted his fingers to remind himself he was alive, to give himself the hug no one was there to hand him. afterall, we see this distraction of his even in Black Sorrow, where despite hanging off a building, his life depending on the threads of his shirt and the benevolence of the alien holding him, through tears, he watched the comets, disassociating from the situation at hand. (in my opinion, quite unrelated but, his raggedy clothes in the slums are possibly one of the reasons his ANAKT uniform remains so pristine: it was the only nice thing he had.)
then, he was sold off as a gift, and even if the love he had represented as an offering for Valentine's Day, he was sent into ANAKT garden and later, Alien Stage, such a well known, undoubtedly fatal competition. here, he wasn't truly in solitude. did he think he was, even in his last moments? perhaps, but he did have people next to him. people who probably never saw his true emotions. at first, his blank stare in his early years that concealed everything that went through his mind, and then the practiced, facade smile he kept. after all, the only time we've seen him break character was when Till let go of his hand, his love for the idea of love, despite looking so happy right before thinking of it, proving to be stronger than the will to escape and be with Ivan. that is when his lips bloomed into a forced, full of despair and mocking towards himself grin, as if he was mentally ridiculing the idea he had: to escape with his adored one and be with him forever.
except no, that is not the only time. there were two more.
his expression, his last, and one of his first, true smile and the true light in his eyes before dying, shot three times,
and the childlike innocence, carefreeness at the end of his cover of wiege, when he speaks of embracing the sea that sings.
the sea adorned with a familiar teal color.
