Sky Sanctuary

Yellow 13 - The Erusian Ace of Aces.
156th Tactical Fighter Wing Aquila.

Ace Combat 04 - Distant Thunder (Shattered Skies in the US) was the major breakthrough moment in the series that has defined how the games have told their stories, as well as the gameplay format, ever since.
Well, until Assault Horizon of course.

Yellow 13 is, to this day, perhaps the most memorable enemy ace to have graced the series, in no small part because he wasn’t actually a bad guy, nor did he have any animosity towards the player.
The games cutscenes largely feature him and not the player character, so we understood who he was before actually encountering him in combat. He was deeply honourable and developed nothing but the deepest respect for the player character, Mobius 1.

The Yellow 13 livery (along with Mobius 1’s ISAF F-22A) has appeared in every Ace Combat game since Ace Combat 04, even the ones that do not feature the Su-37. 
For example, in Ace Combat 6 it was released as a DLC skin for the Su-33.
Assault Horizon went one better and made the actual Su-37 itself, along with the livery, as DLC.

It’s quite possible that it was Ace Combat 04 and the Yellow Squadron that are responsible for introducing the Su-37 and it’s super maneuverability to an audience beyond hard-core aviation enthusiasts. It was, after all, only a prototype best known for stunning crowds at a few airshows by performing maneuvers thought impossible.
It even went on to make an appearance in Sony’s rather… lackluster… no, let’s be honest, shite movie: Stealth.

To this day, many people believe the Su-37 to be the ultimate version of the Sukhoi Flanker family, even though in reality it’s capabilities are far surpassed by the Su-30MKI and Su-35BM.