One girl on reddit beautifully described the situation with Yu and I decided to share it here: "What if the shoe was on the other foot ? " - Yes , precisely this . Yuu's obsession with Mika is like a mania - it had driven him to the brink of insanity. He kept saying " I see the same scene every time I close my eyes" . The thoughts of Mika haunted him in every waking moment , every night he went to sleep . Mika is his reason to live, just as Mika cannot survive without Yuu ,it is the same for him .As he laid in Yuu's arms dying , Yuu said , " Kill me , just save Mika" . That's it .That is how deep his feelings for him run . Yuu was always filled with thoughts of Mika , avenging him , then on reuniting with him , it was to save him . To ask him to give up on Mika now , when he knows that Mika is the only thing in the world which makes it worth living- is absurd .Of course , Guren's reasoning is understandable - just one person for the world . But how would Yuu feel ? He would not wish to continue without Mika gone. Mika does not possess any self worth - he sees himself as dispensable , and would only be too happy to sell himself - to see his loved ones happy . He is a demon . Vampires who become demons are condemned to eternal hell of reliance of human desires . Mika wouldn't mind - if its for his loved ones he would do it - but how would Yuu feel ? Turning him back was what he strived for , now faced with this choice , if he chooses the world , it would mean that all the emotion he built for Mika would be meaningless. Yuu would never agree to sell Mika out -it would mean denying his reason to live - all these years of insanity , trauma ,self hatred would be completely meaningless , if he agrees to give up on Mika forever. If there is one thing we know about Yuu ,it is that he would never agree to give up on Mika. Original: