When it comes to melee combat, two swords can definitely be better than one. Throw a stun gun on top of that and you've got a seriously terrifying weapon. That's exactly what YouTuber jonathanj9969 did with his homemade double-bladed stun sword.
The stun sword is basically just two small swords attached together with nylon bolts. The stun gun was built in to the handle and wrapped in electrical tape with the plug end protruding so it can easily be recharged by plugging it into any electrical outlet.
I'd probably prefer to have a cable and a charging port on the base of the hilt instead, though, if it were sturdy enough, the two prongs could could provide useful when in super close combat.
Basically, just hit the 'on' switch on the hilt, then push the trigger to zap your enemies while you slice and dice them.
Like any stun gun, this stun sword provides quite a shock, as you can see in the video demonstration below where jonathanj9969 gets zapped in the belly. He also demonstrates what happens when an attacker with two individual swords tries to attack.
Now, strap a couple more swords on the opposite side and you've got yourself the closest possible thing to a real-life double-bladed lightsaber.
Darth Maul approves.