Konstantinos Karamitroudis was born on 12 September 1980 in Thessaloniki, Greece, and is best known as Gus G., guitarist, songwriter, and keyboardist of the band Firewind. Inspired by his father's collection of Peter Frampton, he began playing guitar at eight and switched to an electric guitar at fourteen. His first major break came in 1998 when he recorded a demo that attracted Leviathan Records; he soon joined Nightrage, Dream Evil, and Mystic Prophecy before refocusing on Firewind, which released seven studio albums from Between Heaven and Hell (2002) to Stand United (2024). In 2009 he joined Ozzy Osbourne’s band, performing at BlizzCon and touring Europe in 2012, and departed in 2017. Parallel to the band, he released solo albums I Am the Fire (2014), Brand New Revolution (2015), Fearless (2018), and Quantum Leap (2021), the latter ranking second on Guitar World’s annual list. He partnered with Jackson Guitars in 2016 for signature models and received the “God of Riffs” award at the 2017 Metal Hammer Awards. In 2026, he released his sixth solo album, Steel Burner.