I have played Trucebreaker from Visions of Dawn and not been able to beat the OL, who just bottlenecks the heroes for the 4 turns required for the OL to win. Has anyone been able to win this scenario as the heroes? If so, how?

After my group got trounced by it, they tried to break down what would've been needed to win and while it's not mathematically impossible for the heroes to win, our conclusion was that it needed every move and every roll to be perfect.

It's definitely the most unbalanced quest we've encountered so far.

Edit: I was thinking of the second encounter.

Are you playing it correctly with how the OL gets the fatigue tokens? He only gets one if both masters are adjacent at the end of his turn.

While I have not played this one I can see it as a big challenge for the heroes if they play it early in the campain before they get decent gear. Likely I would do open group of golems or giants.

Yes, the OL only got fatigue tokens when the masters were adjacent at the end of his turn. However, since the masters can begin adjacent on the required tile, that isn't really difficult. So even if the heroes can reach these masters after 2 turns, the OL is already half way to winning already. My wife plays the OL, and after the first 2 player turns, she already asked me to double check the quest rules because it seemed impossible for the heroes. Maybe there is errata?

I just played this quest with my group and they had the exact same issue. I stomped them and it wasn't even close. They were understandably upset and frustrated.

This quest is poorly balanced, which is disappointing because it is a fairly new one. I don't think it was playtested and really needs an errata badly. Even something as simple as the Overlord requiring 6 fatigue tokens to win, or not having the additional open group would be enough.

I managed to kill the master troll to stop the fatigue flow, but eventually they went down to the beast men open group and with knock back creating some space, it wasn't too hard for the OL to get his reinforced troll back in the block hole.

Win to OL!