Even if this could work it may be a little overpowered for maps the have large bodies of water, or maps that you have to go through water in. Because you could be on the other side of the map, lightning the water and kill the person on the other side. This also would not require skill and just be an easy kill. Also the other play would not be able to fight back at all against this attack. It would also be very easy to get people into water just by Knockback II swords, then even if they are 30 blocks away in the water and you lightning it you get a non-skilled easy kill.