"Like minions, the brains of these humans are easy to manipulate. Their leader is the key! Take him out!" — Gnarl during the siege of Nordberg.
A Centurion is a commander of a legion of Soldiers for the Glorious Empire. In battle, they wield a sword and a shield. The centurion will usually take a position elevated above his troops to give orders to them.
Soldiers in formation are much less likely to panic and break formation when a centurion is nearby. If possible, it is best to take out the centurion before attacking the formation, since a strong soldier formation can be tough to break.
They can take quite a lot of damage, but are extremely vulnerable to fire. Browns and Reds are the best minion types for getting rid of a Centurion and a mix of them will do a lot of damage. Defeating a centurion will lower the squad morale of the legion they are commanding.
Note that frontal attacks by the Overlord will do damage only if the Centurion is readying an attack, otherwise his sword and shield blocks the attack, but hitting him from the side or back does cause significant damage.
Centurions are very flammable, so catching one on fire with your red minions is very effective at taking him down. Your spells will also work well.