Astral Projection

There is a way for the mortals to access the many other realms that surround the earth and therefore commune with gods, spirits, daemons and other creatures beyond the scope of their common reality. Only several few posess the talent to do so and it is the most common way to perform magic, even though magic on its own is an extremely rare talent among the mankind.
In order to be able to project your mind and soul into the beyond, one must shatter and know how to put the pieces back together. The realms beyond the reach are like that for a reason, a mortal body is not built to enter or in any way exist within them. Magicians need to learn how to split themselves into pieces that would fit where they want to go and at the same time, not let the rest of them wonder or be snatched away by the more nefarious creatures lurking in the backround or the shadows.
With focus and dilligence and the proper guidance, one is capable to divide their consciousness into various pieces and access each and every one of them and send them on their way, depending what kind of spell they wish to perform or what kind of a being they wish to consult. Each realm has its own challenges and dangers and also glittering rewards - and each shard can do many things, different from its other counterparts.
While a person is under the influence of a shatter it is not unusual to see them speaking in multiple tongues at ones or perform physical feats that wouldn't be normally possible to do with a human body. On many occassion this could be mistaken for being possessed but it is better to stop a shatter than to let a demon go walk among us.
Beware.