There are separate shortcuts for the regular version of Divinity 2 and the one with the Developer Mode cheat menu. Hit F11 in the Developer's Cut version (there is a warning in the main menu that some cheats can cause problems, ie skipping past main plot quests, etc) to bring up the cheat window and enable 'god mode'.
Alternately, you can lower the difficulty level.
Playing on nightmare it took me a couple tries to get the technique down. Dragon Dash helps, which I forgot to use since I never really used it all game. Part way through you get a new skill, though I left the zeppelin to pick their own 'bombardment' targets (I was generally too far ahead of them to be able to use it effectively, anyway).
Use the new spell whenever the cooldown allows (you can cheat to get rid of the cooldown time), against the closest and densest group of towers or nests.
Whenever you clear a section of opponents and there is a break before the next, check the zeppelin's health; if it is low and you are not close to the end point, you may want to reload, otherwise save and continue.
Stabbey posted a
video of the escort mission on nightmare, with tips.
Edited from my post in the Larian forum topic
Who's playing DKS on nightmare difficulty ? For the zeppelin escort, my first attempt used a less than optimal strategy. The zeppelin made it to the point the captain decided to change the plan, but Zandalor barely finished replying when it was destroyed.
I reloaded my save at the start of the escort, and attempted to be more systematic clearing the nests and towers. When available I tried to use the Wrath of the Patriarch on the densest cluster that was relatively close, and then flew around taking out individual structures and smaller groups, and also summoned a wyvern whenever I had a moment and thought of it (which wasn't often), figuring an extra target might help the zeppelin. I started off doing much better, but when Zandalor told me to redouble my efforts I noticed the zeppelin's health had dropped a fair bit. Looking back, I discovered it was mostly passed a platform that I had missed clearing 4 or 5 ballistas from. Rather than try getting to the end I reloaded a save from a few minutes previous, and made sure I didn't miss anything the next time. Somewhere after the mid point but before the final section I went up to level 47. The zeppelin's health started getting a little low towards the end, but they made it as far as they needed to get.
