The sharingan allow the user to see chakra points in opponent body.Kakashi in part 1 explained lee 4 or 5 gates techniques against Gaara .
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Uchiha should be able to copy the jutsu with their sharingan because 8 gates techniques are not blood line related.The sharingan can guide the user to channel the chakra are in the body to unlock the jutsu.You do not need large chakra reserve for this jutsu.If they could copy eight gate then they will not need senju dna to amplify their power.What you think or do you think power of hatred compensate for the level of 8 gate?
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