It's not the first time he's seen Koumyou tear up. He doesn't judge him for it one bit, because he knows where it comes from. He knows the kind of life one has to lead where someone is desperate for someone to look out for them.

And even if they're not kids anymore, and no one helped them then, they got each other now. He just grins at him, even if it's a sad sort of grin.

"How about I fill ya in on any plans I got for workin' on this, an' you promise me you'll never give up on gettin' 'im back if somethin' happens, alright? Don't just say, 'it's what happens'. 'Cause we seen all kindsa things in our lives, even before this train." They both can fight celestial bodies if they want to. If Koumyou loses Devero at any point, he will make sure he gets him back.