honestly, naga is fine for a energy mech. Max those legs. Switch out blue madness.
Make sure you use all E-M modules instead of C-E to increase upgrade space.
Otherwise, there isn't really much too it.
Oh, and if you use an EMP, make sure you got plenty energy cap and regen. if not, you'll end up killing yourself. if you use other torsos like windigo (don't use zarkares, it's no good), you can maybe use a hot flash instead of malice beam if you got your heat stats.
Snack for drone is decent for low-mid rank. if you want got get higher, i recommend switching to face shocker or unreliable protector. if you can get railgun, unreliable guardian, or windforge, that'd be great also. (also make sure you got plenty hp for backfire)