The arc lightning damage does more than his default. It's also better because you can charge multiple targets and then they electrocute eachother. Another reason it is better is because you can charge an enemy in a crowd then get behind cover, punch another enemy near you, power up a Blitsfaust Electric trap, pull a lever, overload something with Aleph, run away, file your cyborg nails, scratch your old robot balls, etc...all while electrocuting enemies. In other words, you don't have to actively aim and engage them with your weapon with Lichtbogen, you are free to perform additional actions while killing enemies.
You can also charge multiple target on different parts of the map. The end phase of A Breath of Hope where you fight the three guardians you charge all three of them and as their zipping around the map you activate the charge in them and they send arcs of electricity to all the Wardog mooks running around and to each other. And to keep the upkeep you just have to zap one for a second to refresh the charge. Especially if you have the card that increases the reach of his arcs or initial beam from gun.
Kuzman is a fucking beast.