one does wonder though, he got stabbed through the hands….how can he snap?
that had to hurt.
Yeah I imagine it hurt like a bitch but this is the man who was stabbed through the stomach, basically set himself on fire to burn the wounds closed, carved a transmutation circle into the back of his hand using god knows what kind of sharp object and then walked quite a long distance and remained standing for at least five minutes whilst he killed a homunculus.
In both of these instances Roy must have been in a lot of pain but he ignored it because he needed to help people he loved who were in danger. I have this headcanon that although it’s a sort of running gag throughout the entire series, Roy hates nothing more than being seen as useless and is actually really affected by people calling him useless. Therefore he’ll do pretty much anything to be of use to people who need him. That’s why, despite being in so much pain and having no eyesight, he still insists on taking part in the final battle; because he wants to be useful.
This all links back to his promise: “I’ll do anything in my power to protect the people I love”.