A unofficial english patch has been released over a year and a half ago at
http://elsallia.com/Games/DerLangrisserSFAM#Patches. I've played through two different paths completely so far, and everything works well, except very minor bugs here and there like the wrong character's portrait being shown during a conversation in one later scenario at one point. Nothing major.
Der Langrisser is one of my favorite games (if only it wasn't so easy though), and this patch has become the reference to this game.
There's four different paths you can take (light, empire, evil, independant) which leads to different scenarios and the story changes, as well as the characters you get. This, along with being able to chose two different classes (with different stat growths, movement, spells...) everytime you reach level 10, makes for incredible replay value. If only the game wasn't so easy, though.
At first, I think it would be better to make Erwin a Hawk Knight from his answers in the intro question test, due to, well, flying and reaching the enemy really fast. See this link for information on what stats and spells Erwin gains, and class he becomes, depending on your answers in the intro questionary.
http://www.gamefaqs.com/console/snes/file/588277/13056
Also, don't forget to turn battle animations off in the game settings, since this is a TAS.
Der Langrisser's music is top notch. Oh, and did I mention it's too easy? But still, it would make for a great run, I am sure. I'm looking forward to see someone give it a try.
P.S. : Be sure to read the readme. The game bugs on SNES9X. However, there's a fix with ZSNES through changing some sound setting.