From my understanding, it's a shield bypassing sword.
Take a hit = full shield, dead pilot.
Edit: No, you're right. The explanation does use "nullifying". For some reason, I thought it was the above ^.
In light of that, it does work (and very well) in sport - but still very dangerous. That is unless you have the control (and the technology works in a way that will allow you) to slash into the "energy field" to nullify it, but not contact the enemy.