<p>There is no reason why Kurama`s chakra couldn`t be absorbed, but as i said, when Naruto discovered Nagato`s hideout, Nagato merely sensed Kurama`s chakra and almost soiled himself. He can`t handle Kurama`s direct dark evil chakra, and that was made pretty clear. If he would try to absorb it, he would go completely mad and it would be game over.
</p><p>There is really almost 0 chance of Pain winning. Most of the times Kurama would finish this battle in less than a minute.
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