<p>@Combat I don the think your scenarios of a battle are all necessarily realistic. (Ironic, since this is fictional. :))
</p><p>Why? Because both ninja here are smart enough to already (at least partially) prep for the fight. Itachi is fast, but Oro is shrewd. He wouldn’t make ninjutsu seals in plain sight in front of Itachi, who he knows can copy the moves with his sharingan.
</p><p>Moving on. Why would itachi pull his Susanoo out from the very beginning? He specifically stated it was his “trump card”. That would imply that it would not be one of his first tactics in any fight.
</p><p>Also, Itachi has this thing where he assesses the opponents. Usually, he starts gauging with Gokakyu no Justu or genjustu. In this case, it may be a more advanced fire technique or genjustu. But you forgot Oro had encountered itachi before. And, this is him in the new era.
</p><p>So, Oro can choose from a variety of options to counter with. He can dispel it himself(the genjustu). He can have edos Konan and Kimi disrupt his chakra and release the genjutsu. He could do a substitution technique that Itachi would have no use of copying, and then substitute with a clone.
</p><p>As for fire techniques, anything to counter it with would result in smokescreens. Oro knows that. So. He could either fling a water technique right back, or a wind or fire technique and overpower itachi’s technique. That is possible. Else, oro could dodge and retreat to a different spot, assuming Itachi doesn’t use Amaterasu.
</p><p>If Itachi uses Amaterasu, then admittedly, Oro appears to be in a deadlock. But he could counter by using the same technique Sasuke used to evade Amaterasu. He could basically then collapse a hole into the earth and start using Doton techniques against Itachi.
</p><p>Meanwhile, itachi would be using more clones to deal with kimi and Konan. They have had virtually no prep, since they would ha=e been summoned barely a minute ago at most. So out would come the explosive tags on the clones.
</p><p>Again, more smokescreens. But Kimi could literally spam his kekkai genkai techniques over and over to pressure the clones by using his spine as a weapon and expanding his other bones. This would buy konan enough time for a whole barrage of paper weapons. Of course, itachi would set these on fire. Another huge smokefest.
</p><p>It works for and against both parties. But oro would be underground, not wanting to risk being caught by genjustu or Amaterasu. So he could spam Earth techniques and Kimi and Konan could blitz itachi in various ways since themselves cannot die.
</p><p>Rigged paper shuriken combined with bone attacks and earth techniques would be bound to catch at least one clone off guard. Even if Itachi barraged a variety of techniques, he would be creating more smokescreens with fire attacks. Therefore, he would try to limit the use of fire, since he would then basically be completely disoriented. So, water techniques would be used along with others. But konan could basically spam explosive tags and paper weaponry over and over again, creating smokescreens intentionally so let Kimi and the rigged shuriken do their job. Additionally, oro could use earth to level whichever people he wanted to up or down so the edos could avoid smokescreens or attacks. (Sharingan cannot see through earth, and even if Itachi did, oro could basically make clones and skedaddle them all underground.)
</p><p>Itachi would be fighting on two levels: above and under the ground. He would recognize it would be a priority to seal away the edos. So he would invoke susanoo with the hopes of getting out the totsuka blade and yata mirror.
</p><p>Meanwhile, Oro would recognize this (sannin and shrewd and strategic) and would scatter a bunch snakes in and around the area of susanoo.
</p><p>Oro’s snakes could signal kimi to activate dance of the seedling fern and get himself and Konan underground as well. The could get under itachi, right under him, and wait right before itachi would activate susanoo. Then, launching an ambus would be child’s play....
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