Here's another short (4-card) Chain of Chapter Quests that I made for Myth. The first two are basically just effects that trigger at the start of the tile, but the last two in the chain include ongoing effects that should mix up the tactical situation and require some decision-making during battles.
I haven't made the "Industrial Evil" Quest Chain yet. It's basically a placeholder for a whole other plot idea that would start out the same but go in a different direction entirely. This lets me get double-duty out of the first Quest card, without increasing the frequency of equipment destruction too much. For now, the fog is toxic and corrupting simply because the area is near the nest of a cockatrice, which are several flavors of deadly depending on which mythologies or bestiaries you read.
The rest of the Quest Chain is fairly simple and self-explanatory. The second Quest in particular is pretty much a guaranteed win. Partly that's to compensate for the hefty punch of item destruction in the first Chapter. This Chain isn't meant to be nearly as difficult overall as the official Story Quests, since it doesn't have a Title reward at the end.
The third Quest is a small tactical challenge that can be solved with Aggressive Movement. It's not particularly difficult, but sloppiness is penalized.
The final step has a built-in triggerable board-clearing ability to offset the dangers of a double-tile, but it comes at the risk of a bad roll potentially killing Heroes.
Edit: Not letting the Heroes actually battle the cockatrice is a bit of a cheat and a let-down, but it's a trick that Mercs/MegaCon themselves used at least twice (with the Innkeeper at the end of "No Rest For The Weary" and the Hermit King at the end of "The Mad King"). It's not ideal, but it means I don't have to stat out a cockatrice and pick out a mini for it.
The flavor text on the various cards pokes some fun at the treasure-grabbing nature of dungeon-crawling games in general. Fitting a story into 4 rules-laden cards is pretty tough, so rather than beating my head against the wall trying to produce great drama, I just went for a little bit of snarky humor.
EDIT: Posting these cards here caused me to think more about them. In retrospect, I suspect I may have put these in the wrong order. It might actually flow more logically if the Petrified Fighters were the first quest, instead of the third. You find evidence of cockatrice trouble, and then encounter the nasty environment only if you intentionally approach its lair to kill it. Changing that now would require major rewrites.