Things have calmed down since what last happened.
Luigi's doing good, Mario's investigating this phenomenon with Boos, and Bowser and co. have remained silent.
Now, we speed up a few days after....

"Heh heh, I'm getting good at this game! Thanks C-Stick!" Luigi said to himself, and to his New 3DS, and smiled.
"Hey, Luigi! Want to play some Mario Party 10?" Mario said, turning on the Wii U.
"Sure, but some more players would be nice, it's getting boring with 2 players, especially Bowser Party mode." Luigi said, finishing his round of Smash.
"Yeah... I know! Call Yoshi and Toad to come over! They love Mario Party!" Mario said.
"Yup! I'll give Yoshi a call!" Luigi said, and grabbed the phone.
"Hello?" Yoshi said, answering the phone at his house.
"Hey Yoshi! Its me, Luigi!"
"Oh, hi Luigi! What's up!" Yoshi said.
"Not much, just wanted to know if you wanted to come over to our house, to play Mario Party!"
"Sure, I'll be there in a few minutes!" Yoshi said and hung up.
"Ok! Yoshi's coming over!" Luigi told Mario.
"Ok!"
The minutes passed, and Yoshi nor Toad arrived.
"Umm, what's taking them so long? I already called Toad in the meantime..." Mario said.
"I don't know..." Luigi said, and at that moment, someone banged the door at a fast pace.
"What? Who is it?" Mario said, and opened the door, to look down to see Toad.
"Oh, you finally came! Any sign of Yoshi?"
"Yeah! I saw him going over to the path that leads to Yoshi's Island! I talked to him, but he simply ignored me!" Toad answered.
"Weird... He said he was coming over here!" Mario said.
"Well, I guess we're not going to play Mario Party?" Luigi said as he turned off the Wii U.
"No wait! We're going to! Ah dangit." Mario said and just then, a News Flash started playing on TV.

Mushroom Kingdom News Network Special Broadcast!
"Hey, hey everyone! We got trouble! A large stampede of Yoshis is heading over here!! And Yoshi himself is on front! Take cover, close your windows, hide your kids, quick!!!" Peach hastily announced and ran off, as the channel went into static.

"What?!" Mario said surprised.
"That's why he was taking so long!" Luigi said.
"And it's not good why...." Toad said and took a peek outside.
The police was all over the road, with shields and spears.
"Wait! You guys are not going to hurt the Yoshis right?!" Mario rushed out towards the Chief, Toadley.
"Only if we have to!" Toadley answered.
Luigi and Toad dashed out, to see Peach arriving there.
"Guys, guys! We're in trouble!" She told the Mario Bros.
"Yeah we know! We'll try to get ready!" Mario said, and looked forward, only to see the Yoshis, Yoshi leading them, charging towards the Kingdom, all with bright red eyes.
"Alright guys! Get rid of this place completely! And don't forget to get the princess! Bowser needs her!" Yoshi declared, and all the Yoshis nodded, and started wreaking havoc. Toads ran everywhere an tried to hide, and houses burned down.
"Oh my goodness! What do we do?!" Peach said, panicking.
"Stop them! Let's go, Luigi!" Mario said, and ran towards the Yoshis, Luigi following.
"Are you sure that's going to work?!" Luigi yelled, while running away with the Princess instead.
Mario stopped when he saw Luigi wasn't following him.
"Of course it's going to work! You've played enough Smash to know!"
"I've only played for a week..." Luigi said to himself.
"... Well, fine then! Super Mario doesn't need his Bro to defend the Kingdom!" Mario said, and before he could prepare, the Yoshis ran over him, and some stopped to beat him up.
"Guys! The Yoshi's caught Mario!" Toad yelled in fear.
"WHAT?!" Luigi and Peach screamed in unison and looked behind, however, Mario was nowhere to be seen.
"What will we do then?!" Peach said.
"Hide, that's what!" Toad said and signaled them to enter the Bros. House.
Toad entered, Luigi following behind.
"Come on, Peach! Quick!" Luigi said, looking through a window.
"I'm there!" Peach said and as she reached the doorstep, two Yoshis grabbed her and dragged her away.
"AAAHHH!!! HELP!!!"
"OH NO! PEACH!!" Luigi yelled scared and attempted to get out, but Toad stopped him.
"What are you doing?! Do you want to die?!"
"What?! No! But Peach! They're going to take her to Bowser!" Luigi said, pointing out the window at Yoshi himself, who was taking her away.
"But we need a plan! We can't just hurry in and obliterate everything!" Toad said.
"Actually, that's a good idea... Let me see if we have some Stars on our item box!" Luigi said, and hurriedly went to the second floor.
In that moment, someone loudly knocked the door.
"Hey! Who is it?" Toad asked, and looked out the window, to see Professor E.Gad.
"Heh, it's me, little buddy! I need to have a word with Luigi, is he here?" E.Gad asked.
"Yeah, come in!" Toad said, and closed the window, and opened the door for E.Gad.
"Ok, so where's Luigi?"
"He's upstairs, looking for some items." Toad said, and in that moment, Luigi hurried down with a Tanooki Leaf in hand.
"Ok! I got this, it may work!" Luigi said, when he noticed E.Gad. "Oh, hey Professor! What are you doing here?"
"Hey there, sonny! There's paranormal trouble again, but not in Evershade!" E.Gad told Luigi.
"Really? I can't quite solve that now, I got a larger problem in my hands..." Luigi said.
"That's exactly why I'm here, the ghostly problem is happening right here, right now!"
"Re-really?!" Luigi asked and dropped the Tanooki Leaf.
"Yeah! I got my Boo Tracker 500 with me, the best thing I could escape with from the bunker!"
"Why would you flee the bunker, that's very safe right?" Luigi asked, puzzled.
"It is! However, one of the dinosaurs that are out there haywire came into my bunker and broke the Boo Container, letting all Boos free! And I had well over 200 of them there... Excluding King Boo." E.Gad explained.
"Those dinosaurs are called Yoshis." Luigi said.
"Wait, Yoshi, Boos, container... Luigi! Do you think this has to do with what happened a few days?" Toad asked.
"What?"
"You and Yoshi getting possesed by Boos!" Toad said.
"Oh Yeah! I think that's it... Possesed Yoshi probably freed the other Boos to take control of the rest and attack us!" Luigi analyzed.
"Well, do you guys think those Boos are inside the Yoshis?" E.Gad asked.
"Sure! Check your device!" Toad said.
"Ok..." E.Gad said, and pointed the Boo Tracker 500 outside, and it started beeping.
"I got one! It's... Inside the Yoshi, that's why he isn't defeated!" E.Gad said surprised.
"I knew it! But, how come the machine doesn't detect the others?" Toad said.
"Maybe there aren't Boos possessing the other Yoshis?" Luigi said.
Suddenly, the Boo Tracker started to shake and beep abruptly, and E.Gad bounced up and down with it.
"Woah woah! 5 more Boos appeared, wait, now 7 more, now 10, they keep appearing! Woahhh!!" He said as he looked at the screen, which showed lots of dots, indicating Boos.
"There's our answer..." Luigi said.
"Well, we need to do something!" Toad said.
E.Gad let go of the machine, which broke down and burst into flames. "Indeed! We need to get the Boos out of the Yoshis so they burn in sunlight! That'll quickly clean the container, heh." He said as Toad threw a bucket of water at the burning device.
"Well, we need to search for something that makes the Boos come out of whatever they're inside!" Luigi said.
"I know!" Toad said.
"You?" Luigi and E.Gad asked.
"Yeah. We all know Yoshis love fruit, right?"
"Yup." Luigi said.
"Well, that's a new fact for me! Pretty nice!" E.Gad said.
"Ok. So, we can get some fruit, throw it at the Yoshis, and they'll quickly regain control of themselves, thus making the Boos burn!" Toad explained.
"Interesting! Let's do it! E.Gad said, and took out 2 Poltergusts 5000, and gave each to Luigi and Toad.
"Wait, why do we need these? It's daytime..." Luigi said.
"Just in case... You know... Some pesky Boo knows their weakness." E.Gad said.
"Oh well then." Luigi said and put the Poltergust on, and so did Toad.
Luigi and Toad, with fruits in hand, stood in the middle of the ravaged Town, where the Yoshis were in other sections.
"Ok, Luigi, are you ready?" Toad asked.
"Uhh, kinda." Luigi said.
"Guys, I see them! And I see Mario! He's not looking quite, "Super", if I do say so myself! Ha ha!" E.Gad said, atop the roof, looking through binoculars.
"Really?" Toad said, and surely, they saw Mario, all destroyed and wounded, running towards Luigi.
"LUIGI! LUIGI! LUIGI!" Mario screamed, and tripped on the ground, and fell facefirst at Luigi's feet.
"Ha ha! What happened bro?" Luigi asked.
"It's bad! The Princess got taken away, but we got her back, then the Yoshis literally catapulted her out of here!! And then Yoshi beat my ass, and a Boo did, it's all a disaster!" Mario yelled.
"Oh..  Well, we have a plan already, with the help of Prof. E.Gad!" Luigi said.
"Hi there Mario!" E.Gad waved at Mario.
"Oh."
"Now, go get a Mushroom at home or something, you look very trashed, heh." Luigi said, and kicked Mario over to the house, feeling that he was the spotlight for once, instead of Mario.
Right in that instant, Peach fell from the sky (literally) and crashed into the house, through a window.
"DAAAOUCH!" Peach could be heard crashing into something.
"Well, she's here!" Toad said.
"But we need to free the Yoshis!" Luigi said as they were approaching.
"Toad, Luigi, get ready!" E.Gad said and entered the attic to see from the inside.
"You guys are very persistent, I see." Yoshi said. "GET THEM!" He yelled and they charged towards the duo.
"Have some fruit power!" Toad said and threw fruit at the Yoshis.
"NINTENDO POWER!" Luigi yelled and blew fruit from his Poltergust.
The fruit fell to the ground and all Yoshis came to a stop.
"Wow fruit!" a Yoshi said, and a Boo got out from him.
"Yeah, a melon!!" Another said, and a Boo levitated out.
They all started noticing, and the Boos got out of the Yoshis, a lot of them started burning.
"AAAHHHH!!! HELP! THE LIGHT!! IT BURNS!!"
"MY EYES! THEY'RE BURNING! and my body too." another Boo said, directly looking at the Sun.
"Oh hell no I'm not burning!" Rubert Boo said as he got out of Yoshi, and took and umbrella out.
"Same!" Rick and Benard said, and took out umbrellas.
"SAME!" Lots of Boos yelled and did the same.
"That's why we have this ready!" Luigi said, and he and Toad activated the Poltergusts, sucking every Boo on their path.
"AAAAAAHHH!!!" Many Boos screamed as they inevitably got caught by the wind of the machines.
"Ok, I think we failed. Just saying." Rick said.
"Of course we did!! RETREAT!!!" Rubert yelled and he, Rick, Benard and less than 5 other Boos flew away, shielded from the sun with their umbrellas.
"Oh yeah, we did it!" Luigi and Toad said, and highfived.
"Good work sonny! Your ghost catching skills are great as always!" E.Gad said, congratulating Luigi. "And you did a nice work, to be the first time you've used this!" He said at Toad.
"Thanks!"
"Damn! That's it! I'm banishing Yoshis out of here! They're on Bowser's side now!" Peach said, getting out of the house, steaming.
"No! Don't! They were possesed! They didn't mean to do this!" Luigi said, attempting to convince Peach.
"Yeah, Peach, take their word, it's most likely true. We've had enough problems as it is." Mario said.
"Fine..." Peach said.
"Ow... My head... What happened?" Yoshi said, and that's what the many other Yoshis said.
"Huh... Long story short, you guys got possesed by Boos and caused chaos all over." Toad summarized.
"Really? Dang... Our reputation must be on the floor..." Yoshi said, and looked down.
"Don't worry, we'll let everyone know what really happened. For now, let's take a rest. Mario! Help me take the Yoshis back safely!" Luigi said.
"Ok!" Mario replied, and helped Luigi in orienting the Yoshis back.

To be continued at Bowser's Castle!

Hey there! Hope you enjoyed the chapter! Put lots of effort into it! Also, the photo at the beginning was made by me! Also, I'm slowly coming back, so don't expect really fast updates, but I'll be sure to bring them, don't worry!
See ya in the next chapter!