Babis "Bob" Katsionis (Greek: Μπάμπης Κατσιώνης; born February 17, 1977 in Athens, Greece) is the rhythm guitarist and keyboard player for the heavy metal/power metal bands Outloud, and Serious Black; until recently he was part of Firewind but as of 2020 he has since left due to personal reasons. He is considered to be Greece's most successful rock/metal keyboard player, being the only musician to ever win the same category "Best Keyboardist" in Greek Metal Hammer's Annual Readers' Polls for 5 years in a row (2006–2011). He is the founder of Progressive Vision Group, a videoclip making company, which has produced more than 90 videos for rock and metal artists since 2002. In 2014 he started his own records label "Symmetric Records" to help bands and artists he produced/worked with in Sound Symmetry Studio release their works. To date, Symmetric Records has 14 official releases, with Warrior Path's "The Mad King" being the most successful.