This is my favourite moment between the Colonel and his Lieutenant. More than Roy saving Riza from Lust after cauterizing his own wounds with his alchemy, more than him hugging her to his chest after she almost bled to death right in front of him, more than her admitting she would choose death over living without him. This moment - blind Roy performing the now familiar motions of his flame alchemy as Riza steers him - this moment steals my breath and heart.
This one shot encompasses so much of the spirit of FMA, the spirit of fighting when you have nothing left, giving everything you’ve got even - or especially - when you’re at your most broken. He’s blind. She just almost bled to death. And still, they won’t let it stop them. He can still transmute. She can still stand. And together, they can still fight.
And of course, the Royai implications. This side of Mustang must be part of why Riza is so devoted to him (God knows it’s why we’ve fallen for him) - he’s selfless when it matters, resolute in the face of the possibility of death, and, in this moment, every bit as determined as Edward Elric.
Their expressions are a whole story in themselves.
Riza is staring resolutely ahead. You can read, in her gaze, the pain and fatigue from her recent injury, her utter refusal to let that stop her, her steely focus, and her immutable faith that, blind or not, her Colonel can still perform miracles.
And Mustang’s face - good Lord, the emotions in that expression. Frustration at his own weakness, rage over his helplessness, guilt, fury, hatred, fear, desperation… and, somehow, despite all that, trust. He must hate having to lean on someone else, literally, but he’s willing to do it if it means he can still contribute to saving his country. And he trusts her. Remember when he unleashed his fire on the ‘inferi’ fighting Ed & co underground, and he made the flames swerve around his allies? His alchemy is based on control. That’s how he transmutes, because he knows his alchemy kills. And he’s done his share of the killing, enough for a lifetime. But now he can’t see to aim, can’t see to control, can’t see to direct the flames around his friends, his allies, his soldiers. Can you imagine the terror he must feel, blindly unleashing his fire and knowing that he has to hit one man out of the hundreds on that field? And if he hits anyone else, their deaths would be on him. But he’ll still do it, because he trusts her to guide his aim.
She’s the only one left he trusts enough to be his eyes.