Scripts

Copy and paste this directly into the main map script (not the unit script, not the combat script):

function FightUnitExp(hero, unit)
 while IsObjectExists(hero) == not nil and IsObjectExists(unit) == not nil do
  sleep(5)
 end
 if IsObjectExists(unit) == nil then
  ChangeHeroStat(hero, 0, 999999999)
 end
end
Trigger(OBJECT_TOUCH_TRIGGER, "UnitExp", "FightUnitExp")

and check it in the game.