This was a very simple event, it was just a Triumph and Treachery battle, using the 'Right of Conquest' battleplan, and 'The Landshoals' Time of War, all of which can be found in General's Handbook 2017. The story was simple as well, basically, some Landshoals drifting around Ghyran drifted over the Vale of Efengie spurring the various powers that be to action.
What was I happy with?
Before events, I often ask players to post a bit of fluff about why their army is participating, and offer a bonus during the event if they do. In the past I have given out Triumph cards (one-per-battle bonuses that you can use by giving the card to your opponent) for things like this, but this time I decided to do something different. After reading each player's post, I went through the Path to Glory book and found a Champion Reward or Follower Reward that fit their story, and awarded it to one of their units. I was very happy with the results, as people seemed to actually use them. Also, they were thematically appropriate, player driven, and fun. So I imagine I will do that again in the future.
What was I unhappy with?
Foreseeing that flipping through the GHB constantly to see the Treachery tables would be obnoxious, I made cheat sheets for the players. Unfortunately, I rushed things and misread the original rules, and ended up creating a very different set of rules for Triumph and Treachery. It caused confusion, and I would venture to say some negative play experiences. So my advice to Narrative Event Organizers here would be to take your time. It's worth it.
We had 7 participants, which was straining the game size a bit, I think it likely would have been better had we split into a 3 player, and a 4 player battle. Also worth noting, there were no hard limitations to what people could bring. I recommended an army of 5-10 units strictly for time constraints. We ended up having a low end of 5, and a high end of 11 (if I recall correctly). To be perfectly honest, the 11 unit player won, but I don't think that was really much of a deciding factor as choice of deployment zone was a lot more important.
Towards the end of the battle, some Chameleon Skinks snuck up behind my Plaguebearers. They managed to steal the board eighth from me after mowing down Plaguebearers with their blowpipes. The Triumph and Treachery rules make it difficult to engage with multiple enemies simultaneously unless you have pretty strong shooting (since you can only choose one enemy per phase).
Archaon used a Triumph card from a previous event to deploy "hidden in the shadows". I assume Dorghar was coiled up inside the ruin? I'm not sure it made sense, but it sure was entertaining.
Again with Triumph and Treachery making it hard to find the time for some combats, early in the battle, the Disciples of Tzeentch summoned some Blue Horrors in combat with a unit of Liberators. Because both the Tzeentch player and the Stormcast player had better things to do, they ended up being locked in combat for quite some time before anybody actually got around to resolving things.
We had 7 players on a 4'x8' battlefield, and the Stormcast Eternals largely deployed in Azyr and waited to ride the lightning into battle. Our battlefield ended up being a little spacious, to the point where the High Elves and Beastmen ended up largely spinning off to have their own little battle.