Found a number of bugs. I ended chapter five with Darkweaver in demon form, and when i started chapter six, he was a demon hunter, with demon hunter skills, and the name Darksorrow. And, most annoyingly of all, he lost silence and crit strike, but didn't gain any skill points, so at level 10 he has level 3 immo, ulti, and level 2 mana burn. he was missing 4 skill points. Also, chapter six, part 2, when i got to the gate i killed it (it wasn't invulnerable), and then Doril attempted to open a already open gate. Also, they weren't hostile to Doril, and when both of my heroes died (the pitlord killed them both in under 30 seconds) the game didn't end, i sat there while they made a circle around Doril because they weren't hostile. And once the timer ran out, i still won, even though me heroes were dead. Overall, a good campaign, but these bugs were annoying, and please nerf the pitlord. Also, fight that i found to be the hardest in Karazhan was the very first one, with the 5 level 9 heroes. I had 2 out of three heroes below 100 hp. This didn't happen in and of the other fights, and the last fight in Karazhan was rather dissapointing, i didn't even need to use and abilities. Also, return is a fail ability, and it seems broken, half the time i use it, it just stays on me indefinitely. I would suggest replacing it with something like Dark Light. Same as the paladin's holy light, except that it deals the same amount of damage it does, but the values are lower. And he can use it on himself. So, overall, the healing with be smaller but the damage would be larger, and he can use it to heal himself, as befits a dark paladin.
Sorry for the wall of text.