I'd seen Elemental power armor before, but today I learned it's also a name for the 2-2.5 meter tall genetically enhanced supersoldiers inside! Sorta like SPARTANs from Halo but more so.
moreso and drastically predating, but yeah. Also less so, too, though, as elementals aren't really special ops or anything like it, at least insofar as anything trying to get by outside an actual mech or heavy armor or whatever on btech battlefields are anything but. Basically just line infantry or somethin', if less suicidal than most IS infantry
Not very much space marine either, though. Iirc elemental gene tweaking and active production was still a thing. Also neither the elementals not their armor were particularly special, near as I can recall. If anything I'd almost draw a parallel to Uruk-hai in power armor or thereabouts.