Zoro and luffy appeared through the portal in a battle position because from their point of view someone was trying to kidnap them or transport them away from onigashima so their nakama would be easier to kill.
Zoro:"who are you and why have you brung us here" as zoro said this he projected a little of his conquerors haki intimidating Yurei to the point of sweating and slightly trembling. But gathering up all of his courage he says
Yurei :" Wait. Hold up a second. I can clearly tell you think I'm trying to divert your plans of beating kaido in onigashima."
Luffy coul see he didn't mean any harm so he said to zoro
Luffy :" OI zoro! Calm down he doesn't have any bad intentions I can tell."
Zoro dropped his guard a bit and was ready to listen to what the boy had to say. That's when Yurei decided to speak up.
Yurei :"luffy and zoro I will tell you now that all your nakama and friends and family are safe currently the world you were in has been paused as soon as you left so nothing new has happened."
Zoro:" Thats slightly re assuring but you haven't even introduced yourself so how and why should we trust you"
Yurei :" if my words aren't enough then let my fighting talk for me."
Zoro smirks and unsheathes his swords whilst saying :" Yeah sure I like this alternative it's more my style.". They decided that luffy should be the referee since he wasn't fighting and begrudgingly he agreed mildly annoyed he wasnt the one that was fighting. Luffy then said :" Let the fighting commence" as soon as he said that zoro blitzed Yurei as he had never encountered this type of speed before. Using the Yurei's un adapted situation against him zoro then came for a diagonal sword slash using one sword (that hadn't been coated in armament haki) knowing something like this would happen Yurei had as precaution activated this ability as soon as luffy uttered commence and because of this the sheathed sword passed straight through him seeing that the sword went straight through him zoro was mildly shocked because there wasnt supposed to be any logias or devil fruits in this world coming from his knowledge so he asked out of curiosity
Zoro:" Hey kid how did you make my sword go straight past you aren't there supposed to me no devil fruits in this world?"
But the only response he got from Yurei was a heavy barage of kicks and punches. Zoro proceeded to guard all the blows with his sheathed sword whilst he did this his grin grew... HE WAS ENJOYING THIS FIGHT . Zoro then decided to amp up his effort to 25%. This increased his speed expanentiolly from its previous point.
Yurei :" Fu-" but before he could finish his sentence he was being attacked by a flurry of sword slashes and out of the hundred that came at him because of his phase ability only 69 landed breaking 20 of his bones and zoro noticed this and thought the fight was over and was about to walk away until a battered and bloody Yurei with a massive smile on his face
Said with excitement in his voice :" where do you think you're going WE'RE JUST GETTING STARTED. " as he said this the ground underneath him started cratering whilst a dark and light Green starting roaring around his body and then he dashed to zoro his blows strength multiplied by ten surprising zoro but zoro finally took out his second sword and parried all of his attacks getting quite excited as a small child was able to push him to this extent zoro then hit Yurei to the other side of the facility making a crater as Yurei came out he charged looked as if he was charging up his final move so zoro decided to do the same. Yurei then started to run towards zoro with what seemed to be a mana scythe. Zoro ran towards him with two sheathed sword coated in haki and shouted :" nitoryuu iai:RASHOMON" . And when both of their attacks met they both stood still for a second but one of them was knocked out from the attack... It was Yurei.