Current members

• Eicca Toppinen - Cello
• Paavo Lotjonen - Cello (1996-present)
• Perttu Kivilaakso - Cello (1999-present)
• Mikko Siren - drums (2003-present, a permanent band member since 2006)

Former members

• Max Lilja - Cello (1996-2002)

Sessional members

• Dave Lombardo of Slayer - drums (2003-2007)
• Antero Manninen - Cello (1996-1999, 2002-present)
• Toryn Green - Lead Touring Vocalist (2008-present)

Guest musicians

• Adam Gontier of Three Days Grace ("I Don't Care") rhythm guitar and vocals
• Corey Taylor of Stone Sour/Slipknot ("I'm Not Jesus")
• Cristina Scabbia of Lacuna Coil ("SOS (Anything But Love)")
• Dave Lombardo of Slayer ("Last Hope," "Betrayal/Forgiveness," "Prologue [Apprehension]," "No Education," "Somewhere Around Nothing," "Resurrection," "Cortége")
• Emmanuelle Monet of Dolly ("En Vie")
• Lauri Ylonen of The Rasmus ("Life Burns!," "Bittersweet")
• Ville Valo of HIM ("Bittersweet")
• Linda Sundblad of Lambretta ("Faraway Vol.2")
• Marta Jandova of Die Happy ("Wie weit" / "How Far")
• Mats Leven of Therion, Krux ("SOS," "I Don't Care")
• Matt Tuck of Bullet for My Valentine ("Repressed")
• Matthias Sayer of Farmer Boys ("Hope Vol.2")
• Max Cavalera of Soulfly, Cavalera Conspiracy, Nailbomb, ex-Sepultura ("Repressed")
• Nina Hagen ("Seemann")
• Till Lindemann of Rammstein ("Helden")
• Sandra Nasic of Guano Apes ("Path Vol.2")
• Till Lindemann of Rammstein ("Helden")
• Tomoyasu Hotei ("Grace")
• Toryn Green of Fuel ("I'm Not Jesus," " I Don't Care") Worlds Collide North American Tour 2008