I just finished Korra and I now know how the Caster from Outlaw Star works. The Caster Gun is a rail gun. A spell is placed into a canister and like with the spirit energy canon by running electrical currents through it even someone with no magical abilities could fire a spell
A lot of series have Electricity being used to either amplify or nullify ki and magic attacks is their any basis to that like could a shock glove be used as a ki blast amplifier