Hashirama.
Itachi has 7 Amatarsu's before he is out of Chakra and he does not have long with susanoo.
Now is he going to be able to burn this?
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Sorry but He does not have enough chakra to burn this all the way to the ground.
And Hashirama's wood clones can only be distinguished by EMS
Itachi is going to need susanoo to defend from Mokuton and that will be a ton of wasted chakra.
Minato can only transport and rasengan is not much when you have Hashirama's healing ability. And He will not know where Hashirama is if their are clones he has to try to distinguish.
Hashirama wins mid difficulty.