After escaping from the battlefield, Kahn's ability stops casting at the beginning of the battle. When he surrenders, it simply resets to level 1 (artifacts and level remain). It becomes impossible to survive the first attacks while playing as Kahn without using hit-and-run tactics. P.S. The carts didn't allow me to win even in the second attempt, despite having 17 levels.
Added after 19 hours and 29 minutes
I was playing as the hero.
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