if kakishi cut the lightning in two wouldn that jus leave twice the amount of lightning to dogde? hit the people behind him? you know like how a actual real folded katana CAN cut bullets, but thats just twice the amount of holes you get. Negating the attack or dodging is better.
With the latest chapter though i feel that their gonna show that kakishi's water jutsu can beat a fire jutsu or sumthing. Because if kakishi used a fire jutsu he may have to remove his mask :O and that isn't allowed.
I agree with the using the mangekyou to just pop off hidan's head into another dimension. But i'm way off topic now.
"Knowing is not enough, we must apply.
Willing is not enough, we must do."
- Bruce lee