The Elemental Defenders

Overview
In the midst of the fury that was the Demon Wars, those days that blasted the lands of Tyren and left them forever scarred, five armors were sent into it, to protect the people and drive back the demonic hordes under the command of the Prince of Darkness.

Pyre, Guardian of the Flame
Aqua, Watcher of the Waves
Terra, Sentinel of the Earth
Aero, Defender of the Air
Xain, Keeper of that which is Not

Each of the five armors is a full-body set of plate, complete with helm, breastplate, bracers, gloves, and greaves. The Defenders represent each of the five elemental forces that make up all of creation, and each has a weapon that matches it's personality and abilities.

Though the Defenders are not sentient, each Defender will call to itself a bearer that matches it's 'personality'. This will, of course, be all the product of random chance and circumstance. Also, the level of power accessable to the Bearer is directly proportional to the power needed to stop the threat that forced the Defender out of hiding. Not every Bearer is going to get to summon massive columns of fire or such just to handle a (relatively) minor foe.

Abilities

Even with their innate differences, all five have common threads that bind them together:

~Before being 'bound' to a Bearer, each of the Defenders masquerade as a coin, which is the heart of the Defender and allows the calling of the rest of it. What form each takes is up to the GM, and after the threat which they defended against is past, so is their time, and they take up their hiding form once more, dropping out of the pocket of the Bearer or some other happenstance thing to make them lose the coin.

~Each Elemental Defender is a 'Spirit Item', in that only the heart must be carried around at all times. However, when combat beckons, the armor can be called from it's celestial storage as needed.

~Each Defender was forged from the raw material of it's element, and thus its Bearer has a limited control of that element. Similarly, the Bearer of each Defender is for the most part immune to the ravages of it's native element.

~Each Defender can negate the basic adverse effects of another Defender's powers. e.g. Pyre calls up a fireball to hit some enemies; the other four will not be affected. Conversely, anything beyond simple usage can and will harm the other bearers of the Elemental Armors, such as Pyre calling a firestorm upon the enemy army.

~Each Defender, being mystical in nature, is also quite light, much lighter than a comparable set of plate. They offer even more protection than normal plate armor however, being exceptionally hard to damage.

~Each Defender must occasionally 'recharge' itself within the element of it's birth, else it will become weaker and weaker as it's powers are used, until the celestial energies are depleted entirely and the Defender functions as a normal set of plate armor. In addition, the 'recharging' process also heals damage done to the armor. Scratches, nicks, dents, all are repaired, which is a good thing, because a normal blacksmith's hammer would shatter before being able to work the divine metal the Defenders are made of.

Mythos of the Defenders

When the world of Tyren was still all one continent of the same name, there arose a darkness from beyond the realms of man. The creator of the world, named Trigu by His followers, foresaw the intense and unparalleled destruction the forces of chaos would cause His world, and thus was He saddened, and had mercy upon the people of Tyren. Thus did He forge and send five armors into the world, to defend and protect it against the forces of evil, which were rallied under the banner of the self-proclaimed Prince of Darkness L'ruhk.

And the followers of L'ruhk waged war upon the peoples of Tyren, who themselves were divided amongst the two sides. On one side were those who sided with Trigu and rallied under the banner of the Five Defenders, whom had each found a suitable bearer for their powers. And on the other side of the battleline were those who stood with the Prince of Darkness, and his Dread Lords.

The fighting was fierce, and each side fought with the zeal that comes from having your Lords and Masters watching you. So dedicated were the two sides that they scorched the very earth with their madness, laying waste to anything they could not keep so to keep it from the enemy. And the Five Armors were present, and banished innumerable numbers of demons and Dread Lords from this world to the next, but even they could not be everywhere, and so both sides fought to a stalemate.

It was then that those of Trigu's faith discovered that the Prince of Darkness was amassing a great army which he planned to lead onto the field himself, and they immediately began planning a counterattack. In that great and final battle of what is now called the Demon Wars, so great was the Defenders hatred of the Chaos within L'ruhk that when called upon to fight the Dark Prince himself, they summoned a meteor from the depths of the heavens to smite what they considered a blemish upon their world.

And thus was the battle won, but at a terrible price, for the continent had been cracked by the forces unleashed in that impact which laid waste to both sides. And thus were the Defenders separated as they had the now three continents, their purpose of fighting L'ruhk completed. And soon knowledge of them passed from history into legend, from legend into myth, and from myth to near obscurity...

A Final note

While the armors are humanity's defense against darkness, the armors are also going to force the Bearer to grow in at least one area that they're weak in amongst the course of fighting evil. It doesn't do just to have a defender that will hop in whenever things get out of hand, that defender instead needs to teach as well as save.