"What are you doing?...sigh...I shouldn't have agreed to your plan..." - Sasuke swallowed the antidote which was hidden in his cheek and got up.
Why didn't he just fake it?
Because Eiji didn't want to risk Orochimaru finding it out and canceling the deal before giving him the Edo Tensei.
Of course, Sasuke was against it, but Eiji managed to convince him.
Either way, Orochimaru was sharp enough to suspect that Eiji would have the antidote for Sasuke, so he wasn't surprised.
However, that wasn't the case for Naruto...
"SASUKE!!! ARE YOU ALRIGHT?!" - Naruto
"...Naruto..." - Sasuke looked at him, but after a few seconds he lost his interest.
Unlike in the original timeline, he was strong enough to not feel a rivalry with Naruto anymore, and more importantly - he was solely focused on finally meeting Itachi and get him out of Akatsuki.
"Looks like you won't uphold your part of the deal...so I'll have to take Sasuke by force!" - Orochimaru licked his lips, but still didn't attack, because he wanted to make sure if Konoha would aid Eiji' side or not.
"Hmph! Try it!" - Sasuke stood there in a cool pose, proudly without any fear of defeat.
"SASUKE!!!" - Naruto wasn't sure why Sasuke ignored him, so he finally rushed to him.
"NOO!!! STOP!!" - Yamato tried to stop him, but to no avail.
But since he couldn't stop him with words, Yamato decided to use summon a wood wall to stop him.
"WHAT?! HEY WHAT ARE YOU DOING?!" - Naruto looked at Yamato's concealed face.
"Hoo...this jutsu reminds me of someone...things get more and more interesting..." - Orochimaru
"Hey, how long you gonna stare into the air dumbly?" - Sasuke kicked Eiji's butt, which got Eiji out of his stupor.
"Shit...this situation got more complex now, didn't it? Whatever...we got one of the things we came for, we can get the other just another time... let's ge-" - a fist in his face, catapulted Eiji a few meters away."
The one who punched him was none other than Ukon.
He didn't say anything, but his face told more than a thousand words may tell.
"Looks like, not everyone agrees here..." - Sasuke said aloof.
Eiji got up while touching the location he was hit: "Hmm...well I promised to you that you get your revenge...sigh...fine. Let's just continue with our plan!"
Meanwhile, Jiraiya got back and watched this scene with a headache.
'AHHH!!! DAMN IT!!! NARUTO YOU IDIOT!!!...but the good thing is, at least the enemy doesn't know about me, so I should wait for the right moment to ambush...but this is weird...why isn't Akatsuki making their move now? It really would have been better if this idiot didn't rush in...'
"Isn't it a good chance to leave now? The situation is chaotic enough..." - Hidan
"No... let's wait. We might win the jackpot if we stick around and wait." - Kakuzu
"What? Didn't you say you wanted to leave? You always change your mind every minute...someone like you would never be a good follower of Jashin-sama!" - Hidan
"Like I care." - Kakuzu
Zetsu watched the duo while thinking: 'It's good that they are staying...I didn't even need to convince them...now, let's show me your power Sasuke...'
"Naruto! Listen to me! And you Sakura, as the medic-nin stay get back in case we need you. Let us handle it for now!" - Yamato stepped in front of Naruto and got ready.
"?" - suddenly a wood prison appeared to imprison Sasuke, while Anbu's started to attack Orochimaru and Kabuto with kunais, various water, fire, and lightning release jutsus plus painted creatures.
"Then it's decided that they aren't together!" - Orochimaru transformed into a giant snake and crawled towards Sasuke with a tremendous speed.
"Oh no you won't" - Yamato raised another wood wall to stop Orochimaru to get to Sasuke, who he imprisoned, but Kabuto used the chance to get behind Yamato and almost reached Sasuke.
But Ukon couldn't hold himself back anymore and already in Curse-mark level two, he attacked Kabuto.
However, amidst this, Sasuke and Eiji looked like this didn't involve them.
Eiji spoke towards the entrapped Sasuke: "You deal with Orochimaru and Kabuto like we planned, while I'll deal with your former teammates, alright?"
"Like I care. Just don't take too long..." - with those words Sasuke cut the prison easily down with a Chidori.
CrusadeAgainstFurries
I planned for Orochimaru to revive Minato in this ark, since in Orochimaru's fight against Hiruzen, Hiruzen stopped the third coffin from appearing which was Minato, so when I reread that fight a while ago I thought that it might be a good idea to use it in this ark. But...it's actually not possible since Minato's soul is still with the Shinigami, so it isn't possible to revive him currently. Either it's a plothole by Kishimoto, or Orochimaru was just retarded back then...but looks like I'm as retarded as Orochimaru and need to change a bit what I had planned for this ark 0_0
Fun fact: Orochimaru also could have taken the Shinigami Mask much earlier in canon to make his life a lot easier, but apparently he didn't think about it.
I guess Orochimaru needs a brain-enhancement pill ;)