Hand of Rathmore
The individual powers of the Hand of Rathmore are not clearly defined.
The artifact has a powerful effect on its surroundings and any living creature that comes in contact with it. The Hand generates a deadly radioactive ooze, initially seen in Willard's castle and found in abundance in the final level. Exposure to the artifact generally causes mutation.
Considering the elementalist beliefs of its creators, the Hand of Rathmore should symbolize the Fifth Element, as the other artefacts symbolize the elements Fire, Water, Air, and Earth. It is unknown what the ancients defined as a "fifth" element, and it is also not revealed why the Hand was kept separate from the other four meteor artifacts.