Guardians main task is to tank and draw enemies damage to him, in PvP, this will change though. So what's better transformation to use in certain situation? Here's a brief rundown of the partial transformation you can focus your playstyle to. The Enchance Fortitude and Vitality activated by using the Sadalmelik Head and Sadalmelik Chest respectively focuses mainly on regenerating HP and MP in and out of combat. It is essential and the core effect for the Guardians. Turn this two partial transformation, and you'll turn your Guardian a walking pots-user without using any items at all. A mediocre damage here and there can't hurt at all that's why the Sadalmelik Arm effect, Sharp Attack increases your physical damage and increased Critical Hit.
Movement speed add-ons is still considered as a common day commodity specially chasing down all those adversaries taking pot shots at you. But why do you care, just turn on your Sadalmelik Head and Sadalmelik Chest will give you your Guardian extra meat to take all those damage. Also, being a melee, for you to be effective you must at least get close to your target by running to them with your extra movement speed c/o the Sadalmelik Trousers. If you want to be practical, save all of your CORE by using only your Sadalmelik Head and Sadalmelik Chest for the extra regeneration.
Infernal, demonic, the Red-Devil is just some of the common mistaken identity among Dragonas when a Guardian activated his potent Full Transformation, the Antares. Antares will change this dragon lineage into a eight-face monster from the abyss. Having different faces/head all placed in different parts of his body, will give any enemy the terror they didn't wish to encounter in the battlefield. Antares will give the Guardian new set of skills, among these is the Brutal Grip that will give any unfortunate target a bleeding damage. Also a DoT is the Shout of Terror that will give a constant poison damage in an area. Earth Resonance is another AoE damage from the Antares that will reduce any victim's movement speed and additional damage. Antares Shell is another essential part of Antares' skill tree for it will give the transformed Guardian additional HP and MP regenation as long as the CORE is not yet depleted. Truly the Antares not only will scare you with his intimidating demonic look as well as his battle prowess is where he really shines.