EPTOpen data editor -> go to Unit: Xel'Naga Tower -> under Actors open "XelNagaTower(Unnamend)" and then change "Art - Model", "Art - Model(Build)" , "Art - Model(Editor)" and "Art - Model(Placement)" to Fire Medium
Go to Events - Events + and then take the AnimBracketStart Work under Abil.TowerCapture.SourceStart and change the Msg Type to Set Scale and change values on x,y and z to 1.0
Then go to AnimBracketStop Work under Abil.TowerCapture.SourceStop and change the Msg Type to Set Scale again and change the values of x,y and z to a small number like 0.0001 so it's not visible after deactivation.
In both cases change the "Blend in Duration" to something more appropriate. With the default 0 it will simply change the scale instantly which looks unnatural, changing it to 1 makes it so it grows/shrinks over the course of 1 second which looks much better.
Now go to the unit XelNaga Tower and change UI - Height to the Height you want your Fire to be, cos you can't change its height after placing it like you can with a doodad. I wanted the fire on top of a Temple Column so I chose a height of 3.3 for example.
Now it's time to place your fire cos you have the appropriate height.
After placing it go to the Unit XelNaga Tower and its Actor XelNagaTower(Unnamed) again and change x, y and z values in Art - Scale to a very small number like 0.0001 so it's not visible (this is the last step cause now you won't be able to see the unit when placing it anymore).
Congrats, you just made a custom watchtower in probably something like 2 minutes! :D
