Do you have the camera lens set to 50, or is it still on 35? The latter can make things seem like tiny toys while 50 makes them look more huge.
The crystals are a nice touch. I’d make the cables connecting the crystals to the weapon proper more massive, currently they do not seem to large enough to carry huge amounts of technobabble crystonic energy. Maybe a bundle of cables,with wrappings. And the crystals definitely should glow.
A few crackling lightning bolts would add to the effect. There is a tutorial here on a quick and dirty way to add lightning bolts in Blender.