Minato Namikaze-High class shinobi, great analyst from the way he could counter Tobi, can basically predict his enemies as seen when he knew A would go after all his marked Kunai so he marked B, he knew that Tobi will try to touch then warp him and he acted to counter then defeated him, this is a man that is usually always a step ahead of his enemies, in all his battles the very second he has any sort of information on them. Its pretty widespread information that Sharingan users are short range genjutsu users, That is fact no 1. I'm a fan of Minato even I didnt know he could do anything when A went after his marked Kunai. Minato will know about Uchiha casting genjutsu with their eyes and go long range. He can throw Kunai from anywhere. Itachi will either block the kunai or dodge them, however it doesnt matter because aall Minato needs is one close enough to Itachi, FTG is a well known tech so Itachi will know he'll try to teleport out of Kunai so he wont block but dodge so Minato cant appear near him but any kunai dodge is another marking of the battlefield, in due time Itachi will ot have anywhere to run and Minato can teleport to those already thrown kunai to throw his kunais at a range closer to Itachi, Itachi can't take this opportunity to genjutsu him because will he may expect it, he cant know which Kunai Minato will teleport to, he cant know where his opponent will come from, Minato will Itachi appear near one of the Kunai close to Itachi and throw more kunais at him, Itachi will be more concerned with blocking the fatal kunais or dodging them rather than casting a genjutsu which will allow the thrown kunais to come dangerously close to Itachi, he will have no time to react when Minato teleports again because he still wont know which kunai he will come from, Kakashi is very fast but the range that Pain launched that nail at Kakashi was too close for Kakashi to dodge so hhe used Kamui, Minato at this point will be at that range for Itachi and Itahi wont have time to react or dodge, at most he block the Kunai but Minato can appear behind him even if the marked kunai is in front of him and kill him, another option for Itachi is to use Susanoo to block the Kunai but Minato will still teleport to it and if he cant attack because of Susanoo, he'll think ahead and mark Itachi before teleport far away to avoid a genjutsu being cat on him, at this stage of the battle its already over as Minato can teleport into Susanoo and kill Itachi without a doubt. He wont have time to use Amaterasu because in the fight I've narrated above, Minato will not give him the time to prepare it, if Sasuke could hinder his preparation of it with a rigged shuriken, Minato can with a flurry of kunai, and he cant use the Goukakyu to buy time like he did with Sasuke because while Gokakyu can block some kunai, it cant block all of them and Itachi will want to avoid any one getting behind him at all cost, he wont even have the time to form the seals since he's being continually attacked so any thing is of his techs are out of the question since this is literally the fastest jutsu in recorded shinobi history, Ive never even heard of an opponent forming seals while facing Minato.
