Disclaimer:I don't own Fullmetal Alchemist.
When Al was three, he distinctly remembered accidently cutting his hand against a particularly sharp piece of rock. The blood was warm and stung him, and he remembered Edward worriedly berating him.
It was the first time he remembered bleeding.
This is different.
His metal shell (body isn't a word he likes to use) is hard and thick and doesn't bleed. It can scratch and break and shatter, but it cannot bleed.
When Marda got inside him, it felt... different. Like being filled, having someone with a sharp tongue and sharper skills in him, talking with him, making him feel a little less alone because there's a heart beating inside of him, even if its not his.
Now he's bleeding blood that's not his, its spilling out all over his armor like creeping warm rust and he wishes he could cry. A sword was stuck in his throat and he didn't die, didn't even feel it as a sword barely nicked the bottom half of his torso.
But inside, a heart stopped beating within him.
And oh God oh God oh God there's a dead body inside of me is all he can think of, and he tries to scream and wishes he was choking on the blood that's spilling out across what works for his gut.
He knows he should get her out of there, bury her someplace where she can finally get what she deserves, maybe next to what remains of Greed and her friends. Maybe someplace near his mother.
Instead he keeps her, like a child unwilling to let go of a dead pet because God damnit she's not dead, she's just sleeping!
If he keeps her inside, just a little longer, he doesn't have to look, but he can feel the absent heartbeat, silence inside a hollow shell.