Loki is the Norse Trickster god (originally a Jotun till he became Odin Allfather's blood-brother).
He plays some part in Ragnarok, the end of the world in Viking myth. For this reason he is often interpreted as a Satan figure.
Also, the only reason anyone knows any Norse myths is because of the Eddas, two writings on them. One was by Snorri Sturulson, and that writing is deeply influenced by Christianity. In Pagan beliefs, the end of the world is often seen as one being followed by renewal; it was seen differently by the pagans, and so Christian interpretation is, alas, inherently wrong.
Most Wiccans and other modern-day Pagans choose not to pray to Loki. He is the god of change, often change that is very necessary, hard to get through, and unwelcome at the time. Usually Loki's lessons are full of mischief, but the overall meaning is good-natured and helpful.
Loki is also, from a different perspective, a distinctly fey god. While the other Norse gods were all unchanging and fixed, as pagan gods usually...

Loki is the Norse God of trickery, mischief, and change; a major character in Norse Mythology. Blood-brother of Odin and traveling companion and friend of Thor; his wife’s name is Sigyn, his children’s names are Hel, Fenris, Jormungandr, Vali, Narfi and Sleipnir. Loki is pleasing and handsome in appearance according to the Eddas. He is renown for his cleverness and for helping the Gods out after he has gotten them into trouble as well as his great ability to make them laugh and cheer them up.

He has domain over fire, and is a master magician, conjurer as well as shape-shifter (In some cases changing gender). Loki is bisexual, having sexual relations with both male and female in mythology. Bearing in mind Loki’s dark side as well as his good one, he is most valuable as a witty, entertaining friend, and a God to call upon.

Loki is not an evil malevolent being or the Norse version of Satan or some fallen angel. The later influence of Christianity on Norse culture resulted in changing the mythology portraying Loki as evil incarnate. This is not uncommon, Christianity often demonizes othe...

Coolest name ever!!!

Old Nordic, somewhat common in Denmark.
Derives from old Norse sigr = 'victory' and nýr = 'new, young'

Other Scandinavian variants are Signhild, Signý and Signa
In Nordic mythology, name of the goddess Sigyn, wife of Loki