Question: What do both Aealo and Rotting Christ have in common?

full_context: Document 1: Destruction (band): Destruction is a German thrash metal band. They have been referred to as one of the "Big 4" of the German thrash metal scene, the others being Kreator, Sodom and Tankard. Along with Venom (UK), Bathory (Sweden) and Celtic Frost (Switzerland), three of those four German bands (Tankard being the exception) are often credited with helping pioneer black metal, by containing several elements of what was to become the genre. Destruction was originally named Knight of Demon, but changed their name in 1984. For most of the 1990s, Destruction was not signed to a record label and was forced to self-produce their albums until they signed a contract with Nuclear Blast in the early 2000s.
Document 2: Sanctus Diavolos: Sanctus Diavolos is the eighth full-length album by Greek extreme metal band Rotting Christ.
Document 3: Triarchy of the Lost Lovers: Triarchy of the Lost Lovers is the third full-length album by Greek extreme metal band Rotting Christ. This album was released in April 1996 on Century Media and was the first album to showcase a steady addition of gothic metal influence to their overall sound.
Document 4: Antestor: Antestor (] ) is a Norwegian unblack metal band formed in 1990 in Jessheim. Credited for starting the northern European Christian black metal scene, Antestor is the only Christian band to have an album released by Cacophonous Records, which has also released records by bands such as Dimmu Borgir, Sigh, and Cradle of Filth. The band's only release on Cacophonous, "The Return of the Black Death", proved influential for the Christian black metal movement, and has sold over 10,000 copies.
Document 5: Darkthrone: Darkthrone is a Norwegian heavy metal band. It formed in 1986 as a death metal band under the name Black Death. In 1991, the band embraced a black metal style influenced by Bathory and Celtic Frost and became one of the leading bands in the Norwegian black metal scene. Their first three black metal albums—"A Blaze in the Northern Sky", "Under a Funeral Moon" and "Transilvanian Hunger" (sometimes dubbed the "Unholy Trinity") — are considered the peak of the band's career and to be among the most influential albums in the genre. For most of this time, Darkthrone has been a duo of Nocturno Culto and Fenriz, who have sought to remain outside the music mainstream. Since 2006, their work has strayed from the traditional black metal style and incorporated more elements of traditional heavy metal, speed metal and punk rock, being likened to Motörhead.
Document 6: Passage to Arcturo: Passage to Arcturo is the first EP by Greek extreme metal band Rotting Christ, released in 1991. It was originally an MLP-pressing only: first edition in gatefold cover; second edition with normal cover. The EP was re-released in February 2011 with "The Old Coffin Spirit (Live)", "The Mystical Meeting (Live)" and "The Forest of N'Gai (Live)" as bonus tracks on MCD.
Document 7: Mayhem (band): Mayhem is a Norwegian black metal band formed in 1984 in Oslo. They were one of the founders of the Norwegian black metal scene and their music has strongly influenced the black metal genre. Mayhem's early career was highly controversial, primarily due to their notorious live performances, the 1991 suicide of vocalist Per Yngve Ohlin ("Dead") and the 1993 murder of guitarist Øystein Aarseth ("Euronymous") by former member Varg Vikernes ("Count Grishnackh"), of Burzum.
Document 8: Thy Mighty Contract: Thy Mighty Contract is the first full-length album by Greek extreme metal band Rotting Christ, released in late 1993 on Osmose Productions.
Document 9: Aealo: Aealo is the tenth full-length album by Greek extreme metal band Rotting Christ. It was released on 15 February 2010 via Season of Mist.
Document 10: Non Serviam (album): Non Serviam is the second full-length album by Greek extreme metal band Rotting Christ, released in 1994.
Document 11: Rotting Christ: Rotting Christ is a Greek extreme metal band formed in 1987. They are noted for being one of the first black metal bands within this region, as well as a premier act within the European underground metal scene. They are also responsible for creating the signature Greek black metal sound prevalent in the early 1990s.
Document 12: To the Metal!: To The Metal! is the tenth full-length studio album by Gamma Ray. It was released on 29 January 2010. To promote the album, the band did a tour with Freedom Call and Secret Sphere. The album was recorded in Kai's own studio in Hamburg in autumn 2009. The band has recorded 12 songs. Ten of them were featured on the regular album release, while the other two were bonus tracks appearing on the different editions of the album. The band described some of the songs on the official website, revealing that there would be a full-throttle number called "Rise", a rhythmic and melodically diverse song called "Time To Live", and a multilayered anthem titled "All you need to know", featuring ex-Helloween frontman Michael Kiske. Other songs mentioned are "No Need to Cry", a song written by Dirk Schlächter about the death of his father, "To The Metal", a song they played on various festivals before the album release and the atmospheric and dense "Empathy". It is the last album featuring drummer Dan Zimmermann.
Document 13: Mortem: Mortem is a death metal band formed in 1986 in Lima, Peru. They are the first Peruvian metal band to have toured Europe and the United States. Mortem’s musical style is firmly rooted in the death metal, black metal and thrash metal of the nineteen-eighties. Mortem's characteristic heavy sound is defined through slow and sinister death metal alternated with fast and aggressive counterparts. Frantic tremolo picking in the style of early Possessed and Death built on passionate rhythmic percussion topped with wailing atonal and melodic guitar solos comprise a potent mix which lives up to the principle of death metal technique to craft pounding ritualistic and spirited death metal. Vocals are forged from guttural rasps and often develop into high shrieks while lyrics deal mainly with the occult and anti-Christianity.
Document 14: Satyricon (band): Satyricon is a Norwegian black metal band, formed in 1991 in Oslo. Satyr and Frost have been the band's core members since 1993. The band's first three albums typify the Norwegian black metal style. Since its fourth album in 1999, the band has strayed from this style and included elements of traditional heavy metal in their sound. Satyricon was the first Norwegian black metal band to join a multi-national record label (EMI).
Document 15: Gorgoroth: Gorgoroth is a Norwegian black metal band based in Bergen. It was formed in 1992 by guitarist Infernus, who is also the only original member remaining, and the band have since released nine studio albums. Gorgoroth are a Satanic band and have drawn controversy due to some of their concerts, which have featured impaled sheep heads and mock crucifixions. The band is named after the dead plateau of darkness in the land of Mordor from J. R. R. Tolkien's fantasy novel "The Lord of the Rings".
ground_truth: Greek extreme metal band