the best lightning user is either yondaime raikage or sasuke. A is just beast and has all of these awesome lightning attacks (Lariet, which he used with Bee to kill Kisame (I don't care if it was a Zetsu clone, it was exactly like Kisame in every way, and therefore Bee and A should be reconized as able to kill Kisame)), and Sasuke developed Kakashi's Chidori until he could use it to death, but in so many varients it didn't become old (as fast). Sasuke also developed Kirin, which would've been a one-hit kill had Itachi not used Susano'o. But if it has to be between Kakashi and Darui, people with a combo element (storm, wood) don't tend to use the elements that make up the combo as much, meaning that a few basic lightning attacks and black lightning may be all Darui ever uses, which means Kakashi is a much more versitile lightning user, which in itself makes him a better lightning user (notice this isn't about strength, who would win in an all lightning battle between them, just who's better at lightning techs.). I mean, just because Itachi has Amatratsu doesn't make him the best fire-user in the world. I'm not underestimating Darui, I'm just saying that Kakashi is a better lightning-style user, as he created his own A-ranked jutsu which has been used many times throughout the seris when he was young (i forget how old he was, and i'm too lazy to look it up). And everyone's talking about "This technique is stronger...". NO! It's not 'who has stronger lightning techs', it's 'who's better at lightning techs', and it has to go to Kakashi. Sasuke has Amatratsu (fire equivalent of Black Lightning) and Blaze Release (his equivalent to Storm Release), so does that automatically make him the best fire-style user ever? Same goes for Darui; he just doesn't match up to Kakashi. Case closed.