In 1984 a German comic entitled Superman’s Freunde #4 (translated as Superman’s Friends) featured Firestorm. Below you’ll find the cover which reused artwork from the cover to Fury of Firestorm #2 by Pat Broderick. The cover text translates as “Firestorm against Black Bison”. It’s such a surreal cover anyway, but with the Mexican-looking “Feuersturm” logo it’s even weirder!
Near as I can figure there were only five issues of Superman’s Freunde and each featured a different hero, so this may have been the only appearance by Firestorm in the series.
My thanks to fellow Firestorm fan Florian Schwalenberg for sending this my way!
Stütze Feuersturm! Fan der Flamme!