At the start of each turn, Belakor must take a Leadership test - if this is failed, then he must charge an enemy if there is one in range that he can see. If there are no valid enemies for him to charge, he must move towards the closest enemy model, stopping 1" away from them if his movement would take him further.
Be'lakor may re-roll all his failed rolls to hit, but must always pursue fleeing enemies that he breaks in combat.