Vortex Sound Research

I'm sure someone's tried this out and managed to make it sound cool but I didn't find anything (mostly because I don't know the search term for it), let's say I track some metal ish guitar parts (what I mean is guitars are playing notes and melodies and not just a chord), and then I use a synth and have it play literally the same guitar parts (either the same octave or one octave higher), has anyone managed to make this work? I feel like you could pull of some really cool stuff with this but I haven't managed to make it sound like anything besides dogshit