Appearance: The Elematrix is a large gold amulet set with a number of gems, and as such appears to be a typical gaudy ornament worn by the ultra wealthy as a way to show off their collections of jewels. When the artifact is activated all of the jewels take on the same color and glow brightly.
Benefit: The Elematrix allows the wearer to assume a form superficially similar to one of four different elementals. Selecting the proper jewel on the amulet activates the transformation, which takes about 10 seconds. The duration of the transformation is 2-3 minutes, and the amulet can be invoked 3 times a day.
Sapphire Air Form: The user becomes very fast and very agile (max out dexterity, agility, etc) as well as seeing their weight decrease 90%. Skin becomes blue, and at times semi-translucent. The user can also fly as their normal walk or run speed, glide and drift easily, and their physical strikes inflict damage not by brunt force, but cold damage.
Ruby Fire Form: The user's skin erupts in flame, typically immolating their clothing and possessions. For inflicting damage, the users strength is effectively maxed out for inflicting damage, and like sapphire form, inflicts fire and heat damage instead of physical contact.
Emerald Earth Form: Endurance, strength, etc are maxed out, and the user takes on a rocky craggy appearance. Their weight increases tenfold, often limiting where they can go. The user also becomes largely immune to non-magical and lightweight weapons.
Pearl Water Form: The user becomes evasive and turns into a sentient water creature. The user can temporarily lose their coherence and slip under doors and through holes as small as a keyhole.
Drawback: The Elematrix is a coveted item, if for no other reason than its material value. Thieves are going to be constantly chasing after it, while mage guilds and the like are going to be interested in obtaining the amulet for their own studies. Whoever has the amulet can expect to live a very interesting life.
Lore: The Elematrix was created not many years ago, so its legend hasnt spread across the entire world yet. It was created by a powerful wizard who made pacts with several elemental beings. He used the amulet to travel to other elemental planes, where his magical potence and mastery of the amulet allowed him to maintain an alternate form near indefinately. He eventually lost the amulet and most of his work was lost. There are many who would pay dearly to find the remains of his sanctum and his research notes and grimoires.
The last hero who carried the Elematrix was a hotheaded young woman named Kosi. She was a well known duelist and master of matched swords. She gained the Elematrix as part of an eleborate bet and used the amulet for a number of years. She principally used only the water form as it gave her a good deal of invulnerability, but still allowed her agility, and the ability to use her weapons.
It was also carried for less than a month by the mercenary captain Bagate the Dragon. The captain favored ornate dragon styled armor, complete down to the clawed boots and clawed gauntlets. He gained the amulet by murdering the previous bearer with poison. He took it, and most frequently used the fire and earth forms and caused no small amount of damage. He toppled two seperate towers, and burned three villages to the ground. Hundreds of people died in his hands. His men accounted for many many more. Bagate the Dragon was eventually stopped mid-rampage by a coalition of mages who fought him to a standstill with summoned monsters while an assassin swooped in and killed him between transformations. The assassin stole the amulet and later sold it at a bazaar.
Twist: The Elematrix is a growable item, its powers can expand with the bearer of the amulet. Its creator was able to make its transformations near permanent, while the Dragon was able to push its duration two three times the normal. There are stones on the amulet that havent been activated, so it is rumored that there are more than four elemental forms in the amulet. Magical theorists theorize that there are para-elemental and meta-elemental forms possible by activating two or more of the jewels at a time.
Inspiration: Ben 10's Omnitrix.