I wish I could properly explain it to you, in a way that would help. Though even knowing the reason behind such actions I doubt would assist you any.
[[Leaning back, mindful of the Glameow as he re-situates to just stare at Karkat through her hair from her shoulders, she sighs and crosses her arms.]]
As detestable as it is...his actions make sense. In relation to himself, mind you. Being the one to kill them, and with evidence of their living thanks to Kanaya appearing in Johto after being dead, he likely feels justified. He obviously had a reason to kill them - whether or not we would think it's right is a different story. What matters is that in his mind, he had every right to do that - and therefore it is likely within his logic that nobody has a right to criticize him for it. Possibly not even have a right to be angry with him. Making it easy to tell people to "get over it".
If I knew more on his relationship with any of them, or perhaps more about him in general, I could likely make a more solid diagnosis. But that is my best guess at this point.
[ACTION]
I wish I could properly explain it to you, in a way that would help. Though even knowing the reason behind such actions I doubt would assist you any.
[[Leaning back, mindful of the Glameow as he re-situates to just stare at Karkat through her hair from her shoulders, she sighs and crosses her arms.]]
As detestable as it is...his actions make sense. In relation to himself, mind you. Being the one to kill them, and with evidence of their living thanks to Kanaya appearing in Johto after being dead, he likely feels justified. He obviously had a reason to kill them - whether or not we would think it's right is a different story. What matters is that in his mind, he had every right to do that - and therefore it is likely within his logic that nobody has a right to criticize him for it. Possibly not even have a right to be angry with him. Making it easy to tell people to "get over it".
If I knew more on his relationship with any of them, or perhaps more about him in general, I could likely make a more solid diagnosis. But that is my best guess at this point.