I’d like to point out how much I love Yuri’s expression here.
He rarely smiles this honestly. It’s not an overly joyful smile or cheeky or teasing, not even laid back like he often does. It’s small, and subtle. It’s plain happy, because their biggest problems are over, they did it. He did it with all of his friends by his side. It’s like a huge relief and a certain pride that they managed to get rid of the Adephagos and secure their world a more or less safe future.
Best of all, he’s here with his best friend. I think this tiny smile is also pretty intimate between them right at this moment, in terms of that he really is glad to have Flynn by his side, to be able to share with him this victory they fought so hard for. In the screencap just before this one, Yuri’s expression and shoulders were a tiny bit less cheerful and upright than when Flynn held up his fist. Then he really starts to brighten up and it does show in his eyes. They did it, together. After all they’ve went through, all the troubles and adventures, they reached their goal and they did it as a team (including the others as well). It’s an important fact considering they had sworn to change their world together - that’s partly why I feel the PS3 version did it right.
He’s finally on equal footing with Flynn, has been ever since their sparring match at Aurnion. He’s achieved such a big goal, not alone, but with his friends, his family almost so to say.
Here, Yuri facially truly shows happiness, as subtle as it is, instead of voicing or even concealing it.