Question: Sigh, is a Japanese extreme metal band from Tokyo, formed in which year, and are credited as being one of the first Japanese black metal bands, producing music in the early 1990s when the majority of black metal came from Scandinavia, a historical and cultural region in Northern Europe characterized by a common ethnocultural North Germanic heritage and mutually intelligible North Germanic languages?

Context paragraphs:
Northwest Germanic: Northwest Germanic is a proposed grouping of the Germanic languages, representing the current consensus among Germanic historical linguists.  It does not challenge the late 19th-century tri-partite division of the Germanic dialects into North Germanic, West Germanic and East Germanic, but proposes additionally that North and West Germanic (i.e. all surviving Germanic languages today) remained as a subgroup after the southward migration of the East Germanic tribes, only splitting into North and West Germanic later.  Whether this subgroup constituted a unified proto-language, or simply represents a group of dialects that remained in contact and close geographical proximity, is a matter of debate.  The date by which such a grouping must have dissolved—in that innovations ceased to be shared—is also contentious, though it seems unlikely to have persisted after 500 AD, by which time the Anglo-Saxons had migrated to England and the Elbe Germanic tribes had settled in Southern Germany.

Swedish language: Swedish (   ] ) is a North Germanic language, spoken natively by more than 9 million people predominantly in Sweden (as sole official language) and parts of Finland, where it has equal legal standing with Finnish.  It is largely mutually intelligible with Norwegian and Danish.  Swedish is a descendant of Old Norse, the common language of the Germanic peoples living in Scandinavia during the Viking Era.  It is currently the largest of the North Germanic languages by number of speakers.

Sigh (band): Sigh (サイ , sai ) is a Japanese extreme metal band from Tokyo, formed in 1989.  They are credited as being one of the first Japanese black metal bands, producing music in the early 1990s when the majority of black metal came from Scandinavia.  They gradually shifted from a traditional extreme metal sound to a more experimental, avant-garde style employing symphonic elements.

Frisian languages: The Frisian languages are a closely related group of Germanic languages, spoken by about 500,000 Frisian people, who live on the southern fringes of the North Sea in the Netherlands and Germany.  The Frisian languages are the closest living language group to the Anglic languages; the two groups make up the Anglo-Frisian languages group.  However, modern English and Frisian are not mutually intelligible, nor are Frisian languages intelligible among themselves, due to independent linguistic innovations and foreign influences.

Admonish (band): Admonish is a Swedish black metal band formed in 1994.  They were one of the first bands in the Christian black metal movement and the first Christian black metal group in Sweden.  While the band did not release anything until 2005, the magazine "Metal Hammer" called Admonish "One of the leading Christian black metal bands" in a 1990s issue which focused on black metal.  In 2006 Admonish achieved some mainstream notice when the twins Emil (guitar) and Jonas Karlsson (bass) both appeared on the MTV Europe show "Pimp My Ride International" on October 6.  On that show, in which their car was modified, the twins advertised their band and Admonish's music was played.  The former Admonish member Per Sundberg was also a guitar-player in Crimson Moonlight.

Scandinavia: Scandinavia is a historical and cultural region in Northern Europe characterized by a common ethnocultural North Germanic heritage and mutually intelligible North Germanic languages.  In English usage, "Scandinavia" sometimes refers to the area known as the "Scandinavian Peninsula".

Parabellum (band): Parabellum were a Colombian extreme metal band from Medellín active in the 1980s.  The band was described by "Terrorizer" magazine as one of the world's first black metal bands, as well as the first extreme metal band from Colombia and one of the very first from all South America.  According to writer Emilio Cuesta, Øystein "Euronymous" Aarseth—a musician associated with the early Norwegian black metal scene—has said Parabellum and Medellín's Reencarnación were both influential to his own band Mayhem.

Emperor Magus Caligula: Emperor Magus Caligula (Magnus "Masse" Broberg; born 23 May 1973 in Ludvika, Sweden) is an extreme metal musician best known as the former vocalist, bassist and lyricist of Swedish black metal band Dark Funeral, performing for the band between 1995 and 2010.  He has also been the vocalist of death metal bands Demonoid, replacing Christofer Johnsson, and Sanctification.  He was the original vocalist for Hypocrisy and has featured in other extreme metal bands including Dominion-Caligula (with former Dark Funeral secondary guitarist Dominion) and God Among Insects.  He has also performed backing vocals for the Swedish black metal band Sportlov.

Proto-Norse language: Proto-Norse (also called Proto-Scandinavian, Primitive Norse, Proto-Nordic, Ancient Nordic, Ancient Scandinavian, Old Nordic, Old Scandinavian, Proto-North Germanic, North Proto-Germanic or Common Scandinavian) was an Indo-European language spoken in Scandinavia that is thought to have evolved as a northern dialect of Proto-Germanic in the first centuries CE.  It is the earliest stage of a characteristically North Germanic language, and the language attested in the oldest Scandinavian Elder Futhark inscriptions, spoken around from the 2nd to 8th centuries (corresponding to the late Roman Iron Age and the Germanic Iron Age).  It evolved into the dialects of Old Norse at the beginning of the Viking Age in about 800, which later themselves evolved into modern North Germanic languages.

North Germanic languages: The North Germanic languages make up one of the three branches of the Germanic languages, a sub-family of the Indo-European languages, along with the West Germanic languages and the extinct East Germanic languages.  The language group is sometimes referred to as the "Nordic languages", a direct translation of the most common term used among Danish, Swedish and Norwegian scholars and laypeople.

Supporting paragraphs: Sigh (band) Scandinavia
Answer: 1989