Obito didn't like the situation, if he cannot enter this barrier then if he get caught in this barrier he won't be able to leave either. His mangekyou gave him the ability of kamui and without it he was nothing. If someone can counter his mangekyou ability then his threat level is of an elite jonin at best. Even though he can use mokuton because of Hashirama's cells, without his Kamui, he is not that big of a threat. Only person able to hurt him after awakening his mangekyou sharingan was fourth Hokage. And now this barrier has the ability to stop him. While he was contemplating about the annoying barrier, the barrier started to fade or more like the person who put up the barrier released it. He saw a figure of a boy coming out.
OBITO: "You must be Sasuke, brother of Itachi."
SASUKE: "Get lost."
Sasuke does not have many ways to deal with Obito. He can seal his surrounding and trap Obito but he still cannot kill him since every attack would phase through him. Sealed area would act as an independent dimension so Obito cannot leave but he still can travel between seal space and Kamui dimension so every attack would pass through him. Sasuke has been dabbling into seals to specifically target Obito's jutsu with help of Kushina but apart from the barrier seal they develop, they have nothing else. Kakashi is carrying Obito's other eye so he can deal with him with the help of Kakashi but for that Kakashi needed to be trained enough. So he decided to ignore Obito at the moment.
OBITO: "Do you know who I am?"
Obito was talking to Sasuke in serious tone, he came to recruit Sasuke. After Itachi's death, he thought Sasuke would be good fit for Akatsuki.
SASUKE: "Of course I know who you are, you are a piece of shit and since author wanted to make you a threat to protagonists, he gave you OP ability."
What Sasuke said was nonsense for Obito, it went above his head.
OBITO: "??...What are you saying?"
SASUKE: "I am saying that you are a piece of shit and you should go fuck yourself."
This was not how Obito expected their conversation would go.
OBITO: "I am Mada.."
SASUKE: "Go fuck yourself."
OBITO: "I am Ma.."
SASUKE: "Go fuck yourself."
OBITO: "Do you.."
SASUKE: "Go fuck yourself."
OBITO: "You are very annoying."
SASUKE: "If you think I am annoying then get lost, why are you still here?"
OBITO: "You know the truth of Uchiha clan, don't you? Since you already know everything, I want to know if you are going to carry out Itachi's will and protect leaf village or you will take vengeance for what they made Itachi do?"
SASUKE: "Why would I carry out the will of a psychopath? No one made Itachi do anything, he made that choice. Do you think he can make up for the sin of killing innocent people and children with the excuse that, they make him do that or he did that to protect the village and his brother? Don't drag me in his crime by saying he did it to protect me.
It is not like you will understand, you are human garbage who attacked a pregnant woman and threatened them with the life of a new-born. I don't know how you can even live with yourself, Itachi at least felt guilty for what he did but not you. You are also going to die."
OBITO: "You think you can kill me? I am Madara Uchiha, your attacks cannot even touch me."
SASUKE: "I will kill you, I will make sure that your plan never succeeds, you will fail and die alone. Even in death you will spend eternity alone in the darkness never to see the people you love ever again."
Sasuke didn't say much, he didn't want to reveal many things to enemies. Today he was going to make only one thing clear, they are enemies.
OBITO: "It seems that we are enemies, it is a pity but what can we do. I guess I can't let you leave then."
SASUKE: "You are overestimating yourself, only thing special about you is your eye, without it you are nothing. I guess it was true about every Uchiha, without their eyes they are useless. I don't know why they become so arrogant, they claim to be strongest clan but got wiped out in a single night and it took only two men to finish the job."
Obito was furious at Sasuke because of his constant provocation and especially the part where he said that he will never see his love one again, so he decided to take care of him. He didn't want anyone to know about him so he wanted to avoid fighting but no one will know he killed Sasuke, everyone will think that two brothers died fighting each other.
Obito equip himself with gunbai while Sasuke open 4th gate as they clash. Sasuke threw a powerful kick which pass through Obito and just when the kick pass through him, he attacked Sasuke with gunbai near his stomach area. At the moment Sasuke hit by gunbai, his hand created rasengan and hit Obito at his right shoulder. Sasuke deliberately took the hit so that he can injure Obito, both of them get thrown away more than ten meters. Obito was shocked, it has been 12 years since he took damage, and both times he was hit by rasengan.
Sasuke suffered broken ribs and many internal injuries. If not for the vitality provided by Hashirama's cell, he wouldn't be able to move. Clothes near the injured area were ripped and his injuries were visible. Obito was also injured, not as badly as when he fought 4th Hokage but still enough to not wanting to continue the fight. However Sasuke was heavily injured so he can finish him off, but the next moment Sasuke's injuries disappeared and only ripped clothes remained.
Obito was flabbergasted, he drop the idea of continuing the fight, he was thinking about the kind of jutsu would give him instant healing, then it hit him that Sasuke must have awaken Mangekyou Sharingan.
OBITO: "We will meet again Sasuke, I will remember you."
Obito vanished from his spot, while Sasuke sighed. He used his mangekyou a lot today, even with the vitality of Hashirama's cell, he was exhausted. He moved in the direction of leaf village.