The reason I love ivantill is not because it's mlm (which seems to be something that the fandom is getting heated about right now) it's because of the yearning, the desperation and the deep unrequited affection and obsession Ivan has for Till. The tragedy of their parting just cuts so much deeper for me than mizisua does.
Mizisua is reciprocated and it's one of the reasons why I can't blame Ivan for calling Sua selfish. In his eyes, Sua has what he wants AND she knows what her death will do. Sua just can't bear to live without Mizi so she'd rather be the stepping stone that allows Mizi a chance to live. She does this knowing full well that Mizi has no idea that Sua is going to die in her place. It is inherently a selfish choice but it is also, in its own way, intrinsically romantic, beautiful and tragic.
Ivan's sacrifice is tragic. That's it. You can't say there was anything intrinsically romantic and beautiful in the way he died for Till. Ivan sang with so much desperation to get Till to look his way. To try and get Till to pay attention and what he got instead was Till simply giving up. Almost as if he couldn't be bothered to even acknowledge Ivan's existence within those moments on the stage. And Ivan just wanted him to look at him one more time without him having to force it. Because Till only looks at him if Ivan gives him a reason to.
They don't have a proper duet and you can't say their final moments together were even gentle excluding that final kiss (more like a peck). Everything about Ivan's sacrifice is tragic. It's not romantic or beautiful; it's desperate. It's a man who couldn't even get the man he loves to look at him until the very last second but still can't stand the idea of living without him.
Mizisua was heartbreaking to see and watching Mizi lose it against Luka physically hurt, but there's nothing quite like the truly tragic sacrifice of Ivan, who remained unloved to the bitter end.
I exist to suffer I fear.
It's even worse if you look at the lyrics for Black Sorrow.
Sometimes, I wonder if Ivan sang this song knowing that this was also going to be how their story ended?
Anyways, that's why ivantill lives in my head rent free.