It's not the same. I want him to be here. [Ken ducks his head, scowling at the floor. He's not actually mad so much as he's trying to repress tears, by trying to displace grief with anger.]

...he called me bright. Nobody else has ever thought I was smart. [His voice is a mutter.] He took care of me when I was sick...he fed me when he caught me stealing from him. He looked after me...he liked me.

[Roy was probably the closest thing to a good paternal figure Ken has ever had. Ken's actual father - who Ken doesn't even really remember - handed Ken over for child experimentation in an effort to turn Ken into a weapon that would save his own ass.]