[Xietor]

There is an actual game ongoing to test the balance of the various heroes. To my knowledge, none has had much of an impact.

The Ancient Master in 1.4, the mod's present version, can be killed by 2 smites.

Really the one who has had the biggest impact is Ryleh Epic Hero who can make laying siege under water a nightmare by assassinating underwater commanders. But with star child's magic duel and mind hunt combo, it is already painful to siege Rlyeh's capital.

But Rlyeh Epic Hero is being toned down a bit in the next version.

The game is now in the late stages and angels and tartarian gates rule the world, not epic heroes.

Nikolai-you do make a good point about the Ancient Master in 1.5. And he will likely not get the shock resist. He will be immune to spells that check mr though, such as mind hunt.
Monks are supposed to be immune to mind control spells. thematic. And at 27 hps, he will be easy enough to kill. Much easier than a 310 hp tartarian gate!

Rigor Mortis can kill all Epic Heroes that are not undead-and it is easy for most nations to cast. Drain life is not resistible. Life for a life.

At 27 hps an Epic Hero should not be able to kill a Nation, though, if the player has a good understanding of the game mechanics.