Here's the link to the movie.
SF2 A New Adventure Zeon Kill
It starts right before I begin fighting Zeon. Originally I wasn't planning on recording it at all, but when I got to that point I thought "what the heck" and went for it. The rest of the battle wasn't very exciting. I lost three characters against the first attack of enemies (the two griffins, the Arch Demon, the Demon Master, and the Horseman). After that the only other unit I lost was the sacrifice I fed to Zeon.
One thing I noticed immediately on the save was that the force I "practiced" with was actually stronger. Despite the better stat progression in this hack compared to the actual game, the save I was using had everyone level 28 or higher and clearly not everyone was promoted strictly at level 20. So this was more difficult.
Anyway, the basic premise is that Zeon activates a little like the Kraken Head does. So if you sack a unit in that death zone Zeon will come running. Then all you need to do is wait for him to reach you and beat him down.
The only problem is the Blue Shaman since he'll use the Healing Rain if Zeon falls below 250 HP. So you need to wait until the Shaman moves and then finish off Zeon (which you'll see me do in the replay).
There's also a bit of luck involved since in one attempt I made at this two of the Demon Masters attacked with Zeon. If you want to watch me humiliate myself with poor planning, playing, and bad luck, along with watching the Blue Shaman use two healing rains on Zeon before I give up and quit, this video is for you. It's with the "power save" I used previously (as in, not from this hack).