Karl started HEMA in 2008, training in italian rapier and sabre as well as sword & Buckler (I.33). Since 2013 he's focusing only on rapier and became the main rapier instructor at Klingenspiel, Vienna. Beeing literally obsessed about Capoferros treatise (mainly because he still doesn't understand everything in it, which drives him nuts every so often).
He's been once critiziced for talking too much in a workshop, but according to him: "If you don't take care to get the small but important details across, then where's the point in an intermediate workshop? Everybody generally knows how to e.g. do a lunge, it's the details that really count to give you the edge over your opponent. And people only remember half of it anyway, so maybe it's better to tell them more?"