The first Offline Tournaments for Heroes 5!

Good luck. As I mentioned above, my Walkthrough isn't perfect and can be improved (but I don't think it's possible to complete this map in 12 days; you can only improve the amount of mercury you collect).

What if you completely forgo collecting mercury? I don't fully understand the details, but analyzing your Walkthrough and Bandit's, I assume that if you can speed things up, Agrael shouldn't take the second Castle and the Druids in the first round. Someone else should do that, and that someone should be bought in the first Elven Castle.
Agrael won't have a full turn, but the purchased Hero1 will, and he might be able to catch up to Agrael before the
second Castle. But again, this fighter needs to level up along the way, using whatever is available. And between the second and third Castles, Hero1 and Agrael will be followed by the Hero purchased in the second Castle, or maybe you need to buy two there. So that between Agrael and Hero1, who took the second Castle, there will be not one, but TWO heroes to form a chain for transferring troops between Agrael and Hero1.
These are just my fantasies and assumptions. shoot-nick and Bandit have a better view from their own Walkthroughs; they have saves.