Marcus is staring at the iconic Straw Hat pirates minus over half the future members. This means he is in the East Blue. The weather would be brutal if he were in the Grand Line.
This also means that he is likely before or after Loguetown, but more likely before since I don't see the Red Line in sight.
Luffy probably already got his bounty since this is after the Arlong Arc.
"Hey, isn't it more polite to introduce yourself first?" Sanji pointed out taking a drag of his cigarette.
Marcus raises an eyebrow before pointing out the obvious.
"You guys are on my island." He didn't really have a need for them to introduce themselves considering he already knows them, but this is a perfect moment for a gag.
"Ah, you're right, sorry. I'm San–" Marcus cuts him off.
"I'm Marcus. I'm 24 and a game designer, my sign is aquarius, and my blood type is ICE." He gave him a whole run down.
"You! Let me at him!" Sanji went hysterical as Zoro and Ussop held him back.
"Stop, Sanji!" Ussop cried out gripping his arm.
"Stupid, Cook!" Zoro gritted his teeth.
"Let go! I'm gonna kick him!" Sanji was thrashing.
"Hmm? I wouldn't do that if I were you." Marcus stared at the blond chef without an ounce of emotion.
Sanji stopped and looked at him before getting a little nervous.
Ussop gulped audibly.
"W-W-Why do you say that?" Ussop was trembling.
"Because I'll die." Marcus wasn't even lying here. A kick to the head from Sanji would probably at least render him unconscious and dead if hit enough times. E- in all stats are dreadful, but a cool thing he learned was that they were based off of One Piece's insane physicality standards.
It would explain the muscle which he previously didn't have any at only E-, so his body was quite a few times stronger than his past self.
"Outta the way, Sanji. Let me rub some dirt in his eyes." Ussop was the one that had to be held back this time.
Luffy was just laughing at the whole exchange.
"You're really funny! I'm Monkey D. Luffy! This is my crew! I'm going to be King of the Pirates!" He declared with a grin.
Marcus could practically feel his charisma in the air. The man who'd awaken the most ridiculous power in the world.
"Roronoa Zoro." He had his eye on me the entire time and mostly at my shirt. He was on guard. Even with the limited combat experience that Marcus possessed, He could tell that much.
"I'm Ussop! The great sniping captain!" He boasted having calmed down.
"Sanji." He took another drag of his cigarette.
"Nami…is that Luffy on your shirt?" She got right to the point.
"Hey! That is Luffy!" Ussop exclaimed in disbelief.
"Luffy just got his bounty and new pirates don't really have clothing lines. Where'd you get that?" Nami asked a bit unnerved.
"Do pirates even have their own clothing brand?" Zoro didn't know what to think. He just felt that there was something off.
"Oh wow! I didn't even notice!" Luffy admitted while laughing.
Marcus looked down.
"Ah, well you could say that I'm a fan. Would you like to come in?" Marcus offered.
The rest of the crew could tell that he dodged the question.
"Okay!" Luffy decided and his crew couldn't help but facepalm. He had his face on his shirt and didn't even bat an eye at him being a pirate.
Marcus invited them inside and sat in the living room. There was enough sofas for everyone while Marcus sat in a recliner.
"You do know that we're pirates and invited us in. Shouldn't you have a better sense for danger?" Nami really wanted to pry since Marcus seemed way too laid back. The others felt the same, except for Luffy of course.
"Well, if something were to happen, then I could only blame that my sense of character was off. Those who aspire to become the King of the Pirates can hardly be a normal pirate." Marcus was acting mysterious and decided to just go all the way with it.
"I guess that checks out," Sanji commented taking another drag, "You said this is your island? How long you've been here?"
Marcus shrugged his shoulders.
"Not long. I am from a faraway place. Could I get one?" Marcus asked surprising Sanji a bit before nodding. He gave him one and helped him light it.
"A faraway place?" Ussop questioned. Luffy looked to be at the edge of his seat in excitement. Zoro looked far more interested along with the others.
"I've seen and heard of places all around the world." Marcus took a drag.
Nami perked up.
"Does that include the Grand Line?" She asked and all of them were focused on Marcus after that.
The man in question smiled.
He nodded.
"Naturally, it's a very fun place." Marcus smiled.
"Fun?! It's called the Pirate's Graveyard, you know?!" Ussop was in disbelief that someone would call the Grand Line fun.
Luffy just laughed and stood up.
"Alright! I've decided! Join my crew!" He laughed and the rest of them groaned.
"Seriously, Luffy?! Do you even know what he does?" Nami couldn't believe that her captain would just recruit anyone they meet.
"He said something about game designing?" Zoro mentioned.
"Oh! Pirates have to have fun, so having someone makes games has to be on the ship. So what do you say?" Luffy nods at his own logic.
Marcus felt very tempted but it wasn't something he seriously considered. The world is very real and he already knew how Luffy felt about having an adventure. Could he really want someone who already knew how over 1000 chapters of his story played out? Rayleigh offered to tell them about the One Piece but Luffy refused.
He knew his temperament well.
"Unfortunately, I have a feeling that you wouldn't want me on the crew given the gift I have." He shook his head.
They all grew confused at his words.
"Gift?" Luffy questioned.
"What are you talking about?" Zoro asked.
Marcus took another drag before taking a sweeping glance at all of them.
He sighed.
"My eyes are…special. I can take a glimpse at them and sometimes I would feel and see nothing, but other times there are things that are impossible to know that becomes clear to me." Marcus explained cryptically.
Nami grew annoyed.
"Why are you speaking in a roundabout way. What exactly are you saying?" She pressed for more and while the others weren't so forward, they held the same intent.
"I mean that I can typically see into the past and future of someone and others that are connected to them, but it depends on the person." Marcus was being deliberate here. Some may say why he is saying so much about something that he shouldn't be speaking about.
This is to naturally build up an ethereal and supernatural presence. His games and how they work are unexplainable. Even Vegapunk doesn't have the technology to send people into another world, a game, and have their real body benefit from it. Would they believe him? Even if they did, would Nami, who is known to be a money grubber, buy it?
Marcus needs money, not just for XP, but also for food and other basic necessities. There is no conversion system. Sure, every 1,000 belly is 1 XP, but he can't convert XP to belly. It's also convenient that once I gain 1,000 belly then I just gain 1 XP. The money isn't lost.
It means that I need more than just XP to live.
The reason he is going so far is to show that he is capable of the unexplainable.
Plus, there is a precedent for it. Just not to the extent of what he knew. The seer at Fishman Island, the mermaid Shyarly could tell the future. Even if it was cryptic.
"Bullshit." Zoro sneered at the level of nonsense he was hearing. While he recently learned that he was a frog at the bottom of a well with his duel with Mihawk, he drew the line with fortune-tellers.
"It looks like he has you beat in lying, Ussop." Sanji shook his head sighing.
"Hey! I don't lie! Anyways, you can tell the future! That's so cool!" Ussop had stars in his eyes and so did Luffy.
"Wow! Really?!" Luffy had a wide grin before he sat down with his arms crossed. "I mean…knowing what's going to happen won't be fun. Sorry." He decided to retract his famous recruitment methods.
"You guys don't actually believe him right?" Nami gave the two of them a look as if asking if they'd been hit on the head as a child.
"Well, we could just ask, right?" Ussop countered and Nami grew silent.
"...I guess." Nami sighed believing it was just nonsense.
Luffy immediately stood up and looked at Marcus.
"Alright! We'll ask questions but no spoilers! Or I'll punch you." Luffy gave him a determined look as he would absolutely follow up on his promise.
Marcus grinned and took another drag.
"Ask away." He stated before letting them have the floor.
Ussop then stood up. While he will never admit it, he did have a tendency to…exaggerate things, but he can spot a liar and knows how to trip them up, so he will be looking to see if Marcus will be vague or just straight up lie.
"I'll start! You said you can see the past and future, and since Luffy doesn't want spoilers, I'll ask about the past. Where was I born?" Ussop asked and the rest of the crew looked at him seeing if he will just say that he was joking.
"Syrup Village. You were born to Bachina and Yassop." Marcus took another drag as if what he is saying wasn't much effort at all.
All of their jaws drop.
"No way…!" Zoro couldn't believe it. He naturally knew of his connection to Yassop and considering what happened with Kuro, it was true.
Ussop sat back down with a disbelieving look on his face.
Sanji had a hardened look on his face and he definitely didn't want to ask the same question Ussop did.
Nami huffed.
"So what? He could've found out about that, especially after what happened with Kuro. Where was I born?" Nami naturally knew that she was saved by Belle-mere and wasn't actually born in Cocoyasi Village, so this should be far more difficult to tell.
"Oykot Kingdom. I don't know who your birth parents are, but you were saved by a marine, Belle-mere, and adopted by her and Nojiko." He explained and then it was her turn to sit down with a shocked look on her face.
"I thought you knew about the past and future. Shouldn't you know who her parents are?" Zoro questioned still taking in the reality that given Nami's expression, he was right on the money.
Marcus shook his head.
"I don't see everything. There are only parts I see. Just like I don't know what you all had for breakfast today nor do I know how long it took for you to reach this island." Marcus explained and they nodded. They also felt relieved since if he did see everything, then wouldn't that just be embarrassing? To see EVERYTHING?
"So it seems you really do see the past at least. Do you know who my parents are?" Zoro never met his own parents and he'd been an orphan.
"Your father is Roronoa Arashi. He was a swordsman and died against pirates and your mother is Terra. She was a bandit and she died due to illness." Marcus explained and Zoro nodded.
Sanji wanted to say something but it could be misconstrued to making fun of his parents, so he decided to bite back his words. It explained why he was such a brutish swordsman.
"My turn! Who are my family members?!" Luffy couldn't contain it and wanted to know.
Marcus took another drag as it was going to be a bit long.