His head cocks at that, then sorrow settles over him - more for his brother than himself. He's never been as uncomfortable in his own form as he suspects his brother is. He doesn't have to know the reason to sense it's truth. He's never asked.

'You would do the same for me.' He knows that, has never doubted it. Why should he? Runyu is his best friend as well as his brother. If they can't turn to each other for something, who can they?