He is the primary unit, who can build structures and gives a bonus in combat to all other units inside his influence range. While he does offer this combat bonus, he is such an essential unit that it is often better to leave him protected behind your lines during a skirmish, as his death often means the end of the mission. The hero character has also got the cunning ability to take control over enemy structures that fall within his command radius. This ability, called convert, is an extremely powerful feature, and if used with some thought can completely sway a battle in your favour. A valid tactic is to storm an enemy installation with your troops, then have the hero follow on behind to convert the buildings to your control while your men keep the enemy busy.
Heroes also bring some role playing elements to the game.
After you have completed a certain number of missions you will get the chance to chose a career path for your hero, be it warrior, wizard, rogue or priest. This choice will influence the characters primary statistics from that point on - a warrior will increase in strength, for example, while a wizard will increase intelligence. Later on, after gaining yet more experience, you must chose an ability to specialise in which will again increase the appropriate statistics. You can also keep some of your other units with you as you progress through the game. These honoured units are added to your retinue, and provided you keep them alive they will develop and grow as you progress though the game.