Finally get to post this, since the Codex is released One of my first official work done for Games-Workshop for the then unannounced Militarum Tempestus Army. As an Imperial Guards collector (I still got lot's of my troops yet to be painted) I was very excited to get to work on this, although back then I had no idea they were going to be in a separate Codex altogether ^^
Wow those guys look like they are a tier above the regular Imperial Guard units, I wonder what their Storm Trooper counter parts look like or are they just regular Imperial Guard army with some elements unique to them?
I mean a Lasgun penetrating Tyranid hides with one shot? That's something impossible unless it's a more powerful weapon that we see here being utilized.
They are actually rebranded Stormtroopers, there probably isn't any normal human (without modification) that is going to be more elite than them. (Perhaps their veterans? Still reading the codex fluff myself)
Well some of the larger and more powerful lightning bolts become plasma in the center and there has been evidence of them burning holes (really more like tunnels) straight through objects, rather than setting them on fire and what not.
However, there is also evidence of the more powerful bolts actually blowing people up because of the moisture content of a person rapidly changing temperature and how fast lightning strikes...