look at the way he is holding Rin, he’s being such a sweet guy, holding his little baby brother
Rin is 100% Mephisto’s favorite sibling
He probably feels more similar to Rin than any of his other siblings.
like I highly doubt anybody who says that he doesn’t care for Rin
like I could be reading into things a lot, but the familial love just radiating from him.
Not to mention this look, he shot the one guy when they suggested basically holding Rin as a prisoner
if you have any sibling headcanons for these two i’d love to hear them
I might even make a siblings or family headcanon thing with him and the twins with my own headcanon’s