As promised, here's the full compilation of Getter Robo Arc volume 1. It includes the Mazinger short story "Relic of Terror" as a bonus chapter. We'll continue on to volume 2 either this week or the next depending on how things go on my end. Thanks to OtherSideofSky for translating Arc volume 1 and thanks to C-K for translating Relic of Terror a few years back. Enjoy!
Getter Robo Arc Volume 1
Mazinger Z: Relic of Terror