In 2008, Valo sang back-up on Save Nuta's cover of "Rock 'n' Roll High School" by the Ramones. The track was a collaborative effort by several prominent Finnish musicians to save youth centers across the country. In 2010, Valo sang back-up vocals on Anathema's "We're Here Because We're Here" album, and remixed three songs with his brother Jesse Valo for the HIM album "SWRMXS". That same year he also mixed HIM bassist Mige's solo album "Cimmerica", which was released under the pseudonym MZ. In 2014, Valo was featured on the track "Whisper in the Chaos '97" by Lullacry, which was released on their compilation album "Legacy 1998–2014". At the 2014 Helldone Festival, Valo rejoined Daniel Lioneye on drums and made his live solo debut under the pseudonym Rambo Rimbaud.