1.) We know almost all there is to know about Kakashi battle-wise, except how he got his MS (hurry Kishi, I want to know...). Darui, we've seen glimpses of what he can be. Kakashi is a genius with massive amounts of battle experience (3rd and 4th ninja wars, missions, including Akatsuki, ANBU). I think his Sharingan is the deciding factor. Darui will be forced to use black lightning and storm release; otherwise, Kakashi can cancel and/or copy any of his water or lightning jutsu. Personality wise, I think their similar given Darui's word was "dull" and "sorry."
2.) Given that the Raikage views strength by fighting prowess and not talking (see Naruto's plea to him before the Kage summit), making Darui his right hand man is a strong indicator that he's one of the most powerful shinobi in the Cloud, and possibly a Raikage future candidate.
3.) I also give the advantage in lightning to Darui, but if Kakashi lands a Raikiri, it's over. This isn't going to be like Sasuke and Bee channeling through swords when there's time to react.
4.) I give the edge in chakra to Darui given that we know Kakashi is naturally low but incredibly efficient based of the Kin-Gin brothers fight and that he was able to use those treasures and live. This doesn't translate to a win so long as Kakashi is more efficient in his chakra usage than Darui, which I think he will be.
5.) Also, we don't know how strong Darui is against genjutsu or performing it, so I'm giving the edge to Kakashi.
6.) Taijutsu, Kakashi ought to be excellent at, and we know he can open at least 1 gate. Sparring with Gai ought to have been excellent training and we know he can do at least the front lotus. I haven't seen Darui use taijutsu, but I'm assuming it's not on Kakashi's level.
7.) Ninjutsu-wise, I give the edge to Kakashi. Not because I think his jutsu are stronger than Darui, but because I think he makes better use of them (1,000+ leads to versatility) and has his Sharingan and even MS. I think Darui's are more destructive probably, but the Sharingan and 1,000+ jutsu lean me towards Kakashi than Darui.
Conclusion:
Darui's exceptional, which is why he could learn the 3rd Raikage's techniques and is the 4th Raikage's right hand man. I feel comfortable saying that many of Darui's lightning techniques are superior to Kakashi's, but I also feel safe saying that Kakashi's genjutsu and taijutsu are superior even though I'm assuming since I saw so little of Darui. However, I feel confident that Kakashi is intellectually superior in tactics as well as more experienced. Finally, he has his famous Sharingan, which is a tool, but a tool he wields better than most Uchiha have done it seems, especially since he was able to obtain the MS.
Granted I'm making assumptions, largely about Darui since I know so little. I'm also curious how Kakashi is on rampage. Feel free to knock my assumptions, because it's all good when there's limited knowledge.
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The winner is Hatake Kakashi, the copy ninja. :kakashi:
