Well...as i played Eisenwald the last time i conquered the Maincastles of the enemy faction near the end of the map, difficult but doable and fun.
No i am on a new playthrough with the mythic and had to notice that they made some changes that make the Maincastles invincible, with the little joke that you can't see the trap until the fight started..because the tactic view don't show it.

+50!armor for all troops
Nightvision&+20In for all ranged troops...
Hercules for all melee...

Did i miss something or is this just a "You're not allowed to win"-setup.

Edit:
Also noticed that the KI is plain cheating for this fight..doing 26 damage with their Bowmann(32 Ranged Attack) against Crossbowman with pavese and 41 ranged defense.
I can beat the casteldefense with potions but no chance to defend the factionleader with the few remaining troops.