Overview

Guardians are the tanks of the freeps.  They sport extremely heavy armor at the cost of offensive capability.  They are usually too hard to kill to exert the effort unless there is nothing else left to kill.  They excel at tacking PvE content such as Tyrants

Tactics

• Guardian damage is pretty insigificant.  Don't worry about it.
• Guardians can stun but it's a reactive based on blocking an attack.  So if you don't attack a guardian, it can't stun you. 
• Guardians can assist their fellow freeps by Shield Walling them.  All damage done to the Shield Walled target goes immediately to the Guardian.  All stuns/debuffs will normally affect the target.  This is quite possibly the best way to kill a Guardian as block/parry/evade/armor does nothing at that point.  When a Shield Wall goes up on a freep, call out "TWO FOR ONE!" and go to town on that target, killing both the Guardian and the target.  Highly encourage Guardians to Shield Wall freeps.
• Guardians will often charge in to draw Creep fire.  If enough people focus up sharply on the Guardian when it runs out of freep healing range, it can go down relatively quickly, but otherwise they should be the smallest threat of all foes.