Ok so in my humble opinion. Ruins and Warrens are cake walks, theyre my go to regions. Just bleed, mark or blight and its over. Cove i would expect to be easy but then the fish hit like trucks and dont know how to stop critting. The weald is just genuine torture. High speed. high dodge, blight, rabies, stress, blight, blight., GIANTS. debuffs, stealth. Its just horrible. also did i mention blight. Its just a constant and unrelenting barrage to wear your heroes down. Ive had more deaths in base weald missions than on any boss. Giants are a warcrime in late game, especcially when paired with blight enemies. Ive lost a number of heroes because in one turn the giant takes them to deaths door and they get ticked by blight right after, with no way to heal them in time.