The Road Back

Here's the regen.

It's just hard to break through there when it's relevant. And the turquoise one is just incredibly annoying, especially considering the map structure, where his heroes with the logo literally reach the portal leading to the center of the player's territory after just 2 turns after being resurrected. It's not difficult – it's just inconvenient. You could adjust his time-based reinforcements, but let him resurrect less often, say, in 5-8 days, depending on the difficulty.

The demons are very tough; defeating all three and also breaking through the garrisons... of course, the imps move before the hero. I'm also with an elven army, which, as I understand, can't be replenished further. I restored Ashes, I'll try to defend there, but I'll probably have to revert to saves before the portal.