This is something a little different from your normal Warcraft Movie and was a 30 second interlude meant for NAC (NoggAholic Collaboration) which unfortunatley was canceled due to lack of time. Its one of many clips I will be releasing that was planned for NAC here in the short future.
In particular, what makes this clip different is camera movement that is unseen in other clip and the use of highly edited gamefiles in ways not seen till very recently (with the release of other NAC clips).
I recommend you watch the clip, which is only ~30 seconds long, before reading below my explaination of each of the scenes
Scene 1 - Flying over Kalimdor Nothing new here
Scene 2 - A Kalimdor where every single texture has been altered its color and critter models have been swapped with the Kazzak model. Also water color was changed via a DBC edit.
Scene 3 - Onyxia breathing flames onto Menethil Harbor. Here the player is standing on an invisible platform right underneath Onyxia. All the flames and onyxia were added in using various custom designed tools and my personal NoggIt to move them where I wanted to on the map.
Scene 4 - Titans were added and fixed into the attack animations on the map file of tanaris.
Scene 5 - An older version of Dopefish's files for My Burning Valentine were used as a base for changing the terrain. Then tons of Kel'Thuzad's troops can be seen to have been added in using some techniques involving Excel and Loadinfo to add them to the file. There was some camera issues with how it was moving so as well an invisible object was added that the camera clips into resulting in a smooth movement that otherwise isn't there (some framerate issues when the game is trying to draw a couple hundred zombies unfortunately).
Scene 5 - My mage is standing on top of the tower at the Crossroads and does an Arcane Explosion (you can see her hands glow right before the explosion). Then a hex edited version of the Arcane Explosion model can be seen to go off (lasts a few frames the engulfing fireball) then it cuts to the crater in hyjal as the explosion fades out.
The tools used for this video can all be gathered here.
The camera movements were done via the use Camera Keys and setting Camera Positions.
Also make sure to check out my other NAC Interlude Clip, Hellfire Armor.