Æther

Æther (pronounced as ear-far and known by less posh people Ether) is one of the original elements. Due to it's age it is completely different to anything that exists today and is beyond the comprehension of all but the most magically talented of people.

History
Æther is said to originate from the beginning of the universe when it swam down from above but made the mistake of not keeping moving and it's lower levels solidified into Gaia. Gaia allowed most of the Æther to drain down to below her while the rest remained and transformed into Neptune.

However something prevented Æther from leaving the universe and so it became trapped here doomed to forever be used to further the whims of mortals.

Present
Æther is drawn upon when using magic and so the presence of the 5th dimensional holes nearby strengthens magic. However it is hard for mortals (especially non-magical ones) to understand and so it is difficult to manipulate directly causing people to use spells.