A/N: First off, special shoutout to Tiger of Darkness for leaving me reviews and taking the time to read my story!

Secondly, I made some edits in Ch. 12 to explain Colombo's sudden appearance with the gang, as well as describing some other details regarding Mario and Tails' injuries since I forgot about them. You don't have to reread everything, but I just wanted to put that out there.

Disclaimer: The plot, my OCs, and everything not related to Sonic and Mario are owned by me. Sega and Nintendo own the property of these franchises and their respective characters.

Chapter 16: The Strange Afterglow

Location: Toadley Clinic

Luigi felt horrible.

After arguing with his older brother earlier, he was cross, yet shameful for misbehaving in front of him, his friends, and his doctor. It was like some evil demon possessed his soul and forced him to act out of character. He couldn't explain why he ridiculed Mario like that. He was only looking after him to make sure his medical condition improved. It was more serious than the times Mario left Luigi at home to clean the house and, more importantly, be safe from danger.

Now, he was snoozing in the hospital bed after concealing himself from Mario, Sonic, Tails, and Colombo. Dr. Toadley and his medical team checked his status for various periods, but avoided starting any conversations given the awkward moment they experienced several hours ago.

It was five in the afternoon as he was resting in tranquility. A small breeze flew into the open window next to his bed. Luigi had to admit, the process worked. He felt relieved that some of his energy back, feeling better than before; that, and the 1-Up Delicacy he was offered as his lunch. His arms and legs have felt slightly better than before, the scars from the electric shocks started to heal, and his migraine alleviated. However, he wasn't 100% healthy and ready to be released from the hospital yet. At the very least, the only thing hooked up to him was a single IV stand to his left. He still had his bare chest bandaged up as well.

Nonetheless, his morale deteriorated because of his actions to quarrel with Mario, and he acted like an ass in front of everyone. He wanted to apologize, but he didn't know how. The guilt roamed his mind as he was asleep. Unbeknownst to the green-hatted patient, a special guest was about to arrive. In fact, two guests showed up to surprise Luigi. One of whom was unexpectedly floating right in front of him. He didn't know until he opened his eyes.

Meanwhile, Sonic and Tails were outside on the hospital entrance steps waiting for a special visitor. As soon as they heard a vehicle approaching the building, the two waved at the driver who pulled up quickly in his Super Poltergust 3001. (1) It was none other than the professor.

"Professor E. Gadd! Great to see you again!" Sonic yelled.

"Ah, Sonic and Tails! Good to see you two as well," replied the elderly man.

"Thank goodness you got our emergency call," said Tails.

"Sorry I was running late. I had to fix some of my contraptions. Then I tried to get here as soon as I could," he added as he took off his helmet and locked his mobile vacuum. "Now let's head inside, shall we?"

The trio walked up the steps and passed through the automatic doors. Dr. Toadley's intern, who was maintaining the front desk, permitted the professor to see the man in green.

"We're glad you were able to see Luigi today. He sounded really desperate to see you," Tails faltered.

"However, we thought it was best for him to stay in bed since he awoke from his coma. He still seemed to be hurt from the attacks several days ago," Sonic recalled.

E. Gadd toyed with his eyeglasses as the three walked past a corner. "I'm more disappointed in myself for not realizing this news immediately. I only found about Luigi's incident from the news report. The poor chap…"

"Oh, so you saw the news report? Did you catch me and Tails?" he smirked.

Tails rolled his eyes and gave his friend an unamused look. "Sonic, that's not the main point."

"Oh, yeah. Sorry," he shrugged.

"Well to answer your question, I did take a gander at both of you. How is Luigi, by the way? He's up and running, isn't he?"

"He was awake at first after three days of not moving. But now, he's not too good. You see, after Luigi woke up, he got into a heated argument with Mario."

"An argument? About what, might I ask?"

"Luigi was determined to talk to you, professor. He told us about what he discovered in his nightmares," the fox answered.

"He's not dreaming about ghosts again, is he?" E. Gadd joked.

"No, it's even worse. Luigi 'telepathically' met with the villain who attacked him and learned some shocking news."

The professor switched to a serious tone when Tails mentioned this. "You mean about the Dark Moon?"

Sonic widened his eyes. "Wait, you know about the Dark Moon incident?"

The three stopped momentarily as they approached the elevators. Tails called for the transportation lift while E. Gadd discussed his explanation. "I'm always a step ahead to learn anything regarding my research on paranormal activities and ghosts. And plus, a fellow guest ran into my laboratory yesterday to tell me about this."

Tails raised an eyebrow. "And who visited you?"

"It was a Greenie ghost, one of the many inhabitants who resides in Evershade Valley, the same place where the Dark Moon shines above every night. Well, that is when it isn't destroyed. And because of that, the ghosts become aggressive and cheeky to any innocent bystander who approaches them. They've handled with Luigi and gave him quite the spooks and tricks. Poor guy didn't recover until after he sucked up King Boo and rescued Mario."

Sonic was confused. "Hold on, wouldn't the Greenie be under control of Myster Edge since he made the moon collapse?"

"Not to be off-topic, but I reckon that this 'Myster Edge' fellow is the one who ambushed the Mushroom Kingdom and attacked Luigi? The one you mentioned in the news report?"

The hedgehog nodded. "Yeah, he also attacked our world as well. That villain managed to steal some of the Chaos Emeralds from back home."

"I see. But anyways, the ghosts are only affected if they are within range of the Dark Moon being shattered," explained the professor. "Those who aren't possessed must have been far away enough so the influence of the moon's disappearance didn't change their behavior. That is why the Greenie is still normal." (2) The elevator bell dinged, indicating the doors to open. As they stepped inside, Sonic pressed the button labeled '2' and the lift began its ascent to the second floor. "I also asked the friendly ghoul to meet me here and discuss more about this dilemma."

"Going back to what you said about the ghosts and them being mind-controlled, that's probably why Colombo was still normal. He wasn't anywhere near Evershade when Edge obliterated the Dark Moon. He's still been the same when we were waiting for Luigi to wake up," Tails concluded.

"Oh, that reminds me. Where is that playful Polterpup?"

"Mario's taking him out for a walk. He looked glum from his encounter with Luigi, and that was after he let out a lot of steam. He told us he needed some time to himself," replied Sonic.

"Hmm… I'm not too worried about the Mario Bros. They are family to each other and it's understandable that they have conflicts and fight amongst themselves every now and then. Soon enough, I bet the two will want to apologize for the mistakes they've made," the professor spoke confidently.

"I sure hope so. I don't like it when Mario and Luigi fight. It reminds of the times where Sonic and I had our own arguments," Tails muttered.

"But you still made up for all of your disagreements and troubles, right?" Tails nodded at E. Gadd's question while Sonic mentally agreed. "So even though it's normal that your lives are never perfect and you may end up fighting with each other, that's the way life is. There will always be problems, but you gotta figure out how to solve them. And usually, the situation gets resolved. If it doesn't, well let's just say that you can't always be mad at your friends or family. It might take some time for the brothers to make up."

As Sonic and Tails hoped for the best from what the professor said, the elevator reached its destination. The doors opened and the three walked out to the corridor to find Luigi's room.

"Luigi's admitted in Room 206. It's a couple rooms down this hallway," Sonic pointed as they guided E. Gadd.

"But we should stay quiet, just in case he's sleeping or still stressed out from this morning," warned Tails.

"I've told that Greenie to meet me here, but I don't see the little rascal anywhere, not even at the entrance. Have you seen him by any chance?" E. Gadd whispered.

Sonic and Tails shook their heads, but suddenly, the three heard a loud shriek coming from Luigi's room.

"AAAAAHHHH!"

The guys knew where that scream came from. Several doctors and nurses down the hallway popped their heads up towards the sound with faces of concern.

"Heh, I think Luigi found him," Tails awkwardly chuckled.

"More like the ghost found Luigi," Sonic murmured.

"Oh, criminy! I've specifically told him not to spook Luigi. Guess I'm gonna have to give him a punishment later."

"How the hell do you reprimand a ghost?" Tails asked with bewilderment.

"Easy! You suck 'em up!" Gadd declared. The Mobian animals dropped a bead of sweat at his answer. "With a vacuum, of course! What were you thinking?"

"Uhh…" they both stuttered.

"Oh, never mind! We should head inside now!"

Mario was outside behind the clinic with Colombo. He was given permission by Dr. Toadley that he could walk and take the dog out for some fresh air, but was told to stay close within the vicinity. An intern was also sent to look over the red patient in case anything major happened to him. As Mario held the leash attached to the Polterpup's red collar, he strolled through the flower fields with a face of grief. He still hasn't forgotten about his argument with Luigi that morning, and every passing minute made him feel worse. He let out an exasperated sigh.

"Why did I have to say that stuff to Luigi? I'm supposed to be his supporting brother, not an overprotective father. And now he's mad at me. I just wished he understood my point, yet I also wished I talked to him calmly."

Colombo was sniffing around the planted Ice and Fire Flowers before noticing the mustached man was unintentionally tightening the grip on the leash. He tugged the rope slightly to gain his attention.

"Huh? Oh, sorry Colombo."

The Polterpup whimpered, wondering what Mario was trancing about.

"Don't worry about me. I'm fine, honest."

Colombo growled as he had a feeling the plumber was lying. His instincts were pinned to the fight he had with Luigi.

Mario sighed in defeat. "Okay, I'm not fine. You happy?"

Slowly, the ghost dog walked up to Mario and sadly nudged his head on his leg. Mario cautiously kneeled down, trying not to strain his bandaged chest. He scratched Colombo's head as he apologized again.

"Sorry, Colombo. I still feel bad for treating Luigi with the way I acted. I shouldn't be aggressive and overpowering when he's my younger bro. And yet, I just shoved him into another state of depression."

Just then, Colombo noticed something from afar. He barked to gain Mario's attention.

"BARK! BARK!"

"Huh? What is it boy?"

Colombo howled towards the strange thing he spotted. Mario looked in his direction and noticed the entity. Beyond the distance was a mechanical robot flying over the outskirts of Toad Town.

"It seems to be heading to the south, towards Yoshi's Island," noticed Mario. "But wait, we don't have robot inhabitants in our world."

As he raised an eyebrow, the Polterpup looked up to the red-hatted man, tilting his head with confusion.

"It's peculiar that a robot is in our dimension when they're usually in… Sonic's world…" Mario's apparent realization sparked in his head. "That robot must have came from Sonic's world via the warp pipe! But if that's the case, then… he must have a Chaos Emerald!" he exclaimed.

As Colombo heard Mario's explanation, his instincts kicked in as he tugged the leash in the direction of the robot's path, growling as he despised the evil mech. But Mario firmly held back.

"Whoa, slow down! Don't you think we should inform Sonic and Tails of this?"

Colombo took a while to realize that was probably a good idea. But before he could respond, the two heard a loud scream from the open window of Room 206.

"AAAAAHHHH!"

The plumber and ghost dog whipped their heads to the loud shriek and noticed it came from Luigi's room.

"Oh no! What happened to him now?! Come on, Colombo! We gotta back to Weegie, fast!"

They made their way back to the advising intern who led them inside the hospital. Right now, Mario was shaking as he thought something worse than a coma has affected his younger sibling.

The hedgehog, the fox, and the professor ran into Room 206 to see what made Luigi scream. And the answer was floating in front of the patient.

"Hey! What did I tell you about scaring Luigi?!" scolded E. Gadd.

The entity whipped his face to the professor's voice and became spooked that he shrieked and ran into the wall as his body vibrated like a gong being struck. (3) After regaining his composure, he shook his head and floated up to the professor. Meanwhile, Luigi was still eye-widened as he was sitting upright after his unexpected wake-up call. Sonic and Tails walked up to their immobilized friend.

"You alright, Luigi?" asked Sonic.

"If you consider waking up from a long nap and having a ghost spook the shit out of you as 'alright', then I'm having the best time of my freaking life," replied Luigi sardonically.

The Greenie floated back to the patient and apologized, speaking in his ghoulish language. Although he didn't speak English, Professor E. Gadd translated his thoughts.

"Zephyr here was supposed to accompany me at the hospital, but I told him to run ahead of me since I was busy with my enhancements. (4) Instead of waiting in front of the hospital, he impatiently floated from room to room to find you, sonny boy. He apparently had something important to show to you. And when he found your room, well, we all know what happened after that. Zephyr says he's sorry. He wasn't intending to scare you."

Luigi sighed and forgave the Greenie. "You're forgiven, Zephyr. But the next time I'm sleeping, please don't show up three inches from my face." The green ghost nodded back in response.

"So what is this thing you wanted to show Luigi?" Tails asked in front of Zephyr.

The Greenie made an indicative sound to answer the fox's question. Pulling from his… 'ghostly pocket', he revealed a spectacular piece of a major artifact in his hands.

Luigi instantly bulged his eyes wide open. "What the?! Is that a fragment of the Dark Moon?!"

"Criminy! It is indeed!" confirmed E. Gadd.

"So that's what one of those pieces look like. Damn, it's glowing with sparks!" Sonic pointed out.

"Certainly, this is one of the broken fragments of the celestial body. Thankfully, Zephyr didn't become mind-controlled from the impact," E. Gadd mentioned as he joined the Mobian creatures next to Luigi's bed. "Assumingly, that Edge figure you referred to must have caused the moon to collapse into six separate elements, just like how King Boo destroyed it in the first place."

"Please tell me that King Boo isn't out of his painting again. You know what happened the last time when you were inattentive with your knickknacks and gadgets," Luigi moaned.

"I'm sure that he's well put in his prison where he belongs," assured E. Gadd as he flicked his hand like it was nothing. "Besides, I don't make that many mistakes."

"You sold his original portrait in a garage sale," Luigi reminded with a hint of annoyance. (5)

"Ehh, let's not get into the details of that discussion."

"Don't you think it's a bit dangerous for someone like Zephyr to hold a piece of what makes him hospitable?" Tails inquired.

"Hmm, you might have a point there, young fox. Here, Zeph. Hand me the Dark Moon piece," E. Gadd requested.

The Greenie transferred the glowing purple piece to the professor who scrutinized its corrupted appearance.

"Out of curiosity, how did he find this piece?" Sonic wondered.

The ghost spoke in his inherited language to explain. And as usual, E. Gadd deciphered his quote.

"So initially, he saw the shadow figure about to destroy the Dark Moon in the sky above Evershade Valley. As he evacuated the region, he was far away enough to avoid being paralyzed under the influence of the moon collapsing. As he floated away, he intended on seeking me for help, so he set off for Boo Woods. And along the way, he encountered this Dark Moon piece in his travels!"

"But where did he find it?" Luigi thought.

The professor paraphrased the Greenie's story. "He located this fragment just outside of Toad Town as he headed towards my lab. When he came by, he discussed about the scene he witnessed and wanted to find Luigi. That was when I got your distress call, Sonic and Tails. You told me that Luigi was hospitalized, but needed to see me. I still had to make some modifications to my inventions before I could set off, so I asked Zephyr to meet me in front of the Toadley Clinic. And now, here we are in this tight dilemma. We do have a piece of the Dark Moon, but who knows where the other five are?"

Just then, Luigi's 3DS, sitting on his bedside dresser, vibrated as it played a notification sound. Luigi reached for his portable device from the bed.

"I'm surprised that your present didn't get destroyed when you fell, Luigi," remarked Tails.

"Well, I made sure that thing's both indestructible and waterproof. It's the perfect type of communicator!" exclaimed the professor.

"Still, it's bulkier and not as simple as our wrist communicators. Besides, we don't have to store them in pockets, or fur in our case," Sonic retorted.

Luigi ignored his friends and opened up the dual screen device. Navigating the main menu, he skimmed through the most recent message he received.

"I just got an email from Daisy!"

"Really? What does it say?" asked the Blue Blur.

Luigi read aloud the message sent by the flower princess.

…

Dear Luigi,

As you may know, we've been kidnapped by that nasty villain, Myster Edge, and have been secluded in a dark cave. According to Yoshi, we seemed to be held inside the Vanilla Dome. And we have uncovered even worse news.

While stuck inside our prison, Dr. Eggman was taken here after being interrogated by Myster Edge. He told us a generalized idea on what that shadow figure has been planning. And that includes the Dark Moon. From what he said, there were five fragments hooked up to a machine. He explained that their power was being drained and transferred into the five white figures who were inside some capsules. We don't know too much, but Toad concluded that the Dark Moon had collapsed and the white entities were the Possessor ghosts you've seen before. But chances are that they're more powerful than the versions you fought in the past.

Eggman also found out that he now has four of the Chaos Emeralds. Apparently one of his brainwashed robots found the fourth one for him. That's all we know so far. If we can uncover anything else from Edge's minions or from himself, I'll email you again.

Everyone seems to be in solitude, unharmed yet uncomfortable in this dank cave. Everyone who was at the party is with me as well: Peach, Yoshi, and all of our friends. And then there's Eggman and his two robot henchmen, of course. Don't worry about us. Believe me, we're all more worried about you. If you're with Mario, Sonic, and Tails, then hopefully you're doing fine. I'm sorry that your birthday ended horribly. None of us expected this to happen. Please take care and I hope you recover soon.

-Princess Daisy-

…

"That's what she wrote," finished Luigi.

"Hmm, that does not sound good at all. If Edge has five of the six Dark Moon pieces and they're being drained off to the ghosts, I can't imagine the chaos they may create in our world," E. Gadd ruminated.

"At least we have one of them. If he had all six, that would probably be disastrous," Tails complied.

"Well, we kind of get why he needed the Dark Moon. He wants to take control of the ghosts like he did with Egghead's robots. And he seems to need the Chaos Emeralds to summon the Oblivion, or whatever Luigi said. And that the fact that he has more than half of them is dangerous to think about. We gotta stop him somehow," contemplated Sonic.

"Should you clean off that dark power, Professor?"

"Ahh, I'm glad you mentioned that, Luigi! You see, I was tinkering with an invention something similar to my Energy Suppressor. (6) Only this one is portable!"

Reaching into the pocket of his lab coat, E. Gadd pulled out a small box with a red button. Pushing the contraption with his finger, the device unfolded and revealed a Mini Energy Suppressor. He set down the invention on the other end of the bed near Luigi's feet and placed the Dark Moon on top of the turntable. Instantly, four small dusters popped out of each side of the box and cleaned off the electrical interference of the violet fragment as it spun around. In a matter of seconds, the piece glowed brightly in its natural form, restored from its negative appearance. After the cleaning process, Elvin grabbed the piece off the Suppressor. The dusters contracted back into the open flaps and the mechanism reduced itself to a small box.

"Wow, E. Gadd! Your inventions never fail to amaze me! I don't know how you come up with these technological advances!" praised Tails.

As he dropped the box in his pocket, the professor couldn't help but chuckle at the fox's compliment. "Hohoho, thank you, Tails! I always come prepared for dire situations. And how convenient was it that I brought this little tool with me."

Sonic was also impressed by the invention. "Nice job, Professor! Well, that's one piece down, and…"

Suddenly, he got interrupted when he felt something strange in his quills.

Tails saw something shining and reacted to it. "Sonic, the Chaos Emerald!"

The hedgehog pulled his hand back and took out the yellow gem that he hid. And what happened surprised everyone. Both the Emerald and the Dark Moon piece shined brightly in front of their eyes. "Whoa!" he flinched.

"Huh?! W-what's happening?" shouted Luigi.

"I don't know!" Tails yelled back.

"Criminy! I've never seen the Dark Moon react like this!" exclaimed E. Gadd.

"I've seen some questionable stuff from the Chaos Emeralds, but this is crazy!" added Sonic.

Then, both the gem and the fragment rose from their hands, floated high in the air, and spun in circles. While circulating above the party, their powers started to emanate and construct a large orb of energy inside their state of motion. Luigi, Sonic, Tails, E. Gadd, and Zephyr were completely confused, yet shocked at this strange occurrence. Just before anyone could react, the orb glided over to the characters.

First, it hovered over Zephyr. Next, it shifted above E. Gadd. Followed by Tails. Then Sonic. When it got to Luigi though, it remained still above his head. Luigi raised his eyebrows as his mouth was agape. Wondering what happened next, he soon got his answer. The powerful ball shined bright once more causing the others to shield their eyes with their arms. And then, the orb dove right into Luigi's body. His eyes were widened, somewhat in a trance, and his body glowed as he felt rejuvenated and stronger than he was before being awakened by Zephyr. The others looked at him as he was stuck in a paralyzed state. A few seconds later, the light dissipated and the room went back to normal. The Dark Moon piece and the yellow Chaos Emerald fell onto the bed as the objects returned to their original forms.

A moment of silence struck Room 206. Sonic was the one to break the silence. "What… the… hell was that?"

"Beats me," replied Tails. "I wasn't expecting anything like that to happen."

"This is far more interesting than what I've seen from my paranormal findings. This is absolutely extraordinary," commented the professor, to which the Greenie agreed as he spoke in his language.

Sonic turned to Luigi, whose eyes were still glued to the wall in front of him as if he was staring blankly into space. "Hey, Luigi? Luigi? You okay?" he asked, waving his gloved hand in front of him.

Luigi blinked his eyes twice before turning to his right to see his friends, furrowing their brows in worry. "I… I don't know what just happened. But that strange energy… It made me feel… alive, and full of energy… if that makes sense."

"Does that mean you can walk?" wondered the twin-tailed fox.

"Only one way to find out."

Carefully minding the IV stand still hooked up to his shirtless arm, he pulled off the covers and shifted his legs to the opposite edge of the bed with ease. He held the rolling stand and dragged it along as he walked past the window and around the bed. Now, he was standing in front of everyone in the middle of the room. The others widened their eyes in shock at this discovery, but started to form smiles on their faces to see the man in green up and about, and healthy too. In return, Luigi curved his lips into a smile of his own, feeling proud of his unexpected recuperation.

Later, the guys all heard a voice from the doorway. "Well would you look at that?" They turned to the entrance and noticed Dr. Toadley. Behind the Toad doctor was his intern, Mario, and Colombo. "Why, I was about to check up on you and suddenly you're standing strong and tall!"

Mario made his way into the room and looked at Luigi in surprise. "Luigi! You're okay!" He ran up to his younger brother and hugged him. Luigi was slightly surprised to see Mario, but he was glad to see his older sibling and returned the embrace.

When Mario released the hug, the two both looked at each other in the eyes and changed their facial expressions from happiness to regret.

"I'm sorry…" they said concurrently. "I am… Well…" they continued to repeat each other's words before Mario spoke up.

"No, Luigi. I'm sorry I made you feel depressed again. I shouldn't have been overprotective of you and act superior over you. I should have reconsidered your needs when you wanted to help our friends. And I didn't mean to make you cry or feel like you're not wanted. It's just that…"

Luigi interrupted him and put his hands on his shoulders. "Mario, Mario… it's okay. I understand you, and I forgive you. I'm sorry as well. I was a big jerk when I yelled at you. You were looking over me for my health and safety and I failed to realize that. Besides, you've been doing that for the past 26 years and I appreciate your support. I had no reason to act like that."

The red-capped man frowned in sadness. "Luigi, I hope I didn't hurt you emotionally."

"Mario, you're fine. I'm fine. I mean, look at me! I'm standing in front of you."

"Yeah, I see," Mario chuckled and looked up to him with a large grin. "I'm so glad you're back."

Luigi mirrored his smile. "Same here, bro."

After their reconcilement, they hugged each other once more. Everyone was glad that the Mario Bros. were back to reconstruct their brotherly bond. As they broke away, Colombo ran up to his owner and leaned his front paws on Luigi's legs. He picked up the Polterpup and laughed as he started to lick his face. Meanwhile, Sonic walked up to his red-hatted friend and hung his arm around his neck and over his right shoulder.

"I'm glad you two made up from your fight. So how are you feeling now, Mario?"

"After what I saw, better than ever, Sonic," he replied happily. "But I do have to wonder… What the heck did I miss? Why is Professor E. Gadd here? And how did Luigi even recover that quickly?"

"Well, bro, it's quite a long story. We might as well tell you from the beginning," his brother responded.

END OF CHAPTER

Alright! Luigi is up and running and repaired his bond with his brother! We will return to these guys as they explain to Mario the conspiring events before he came into the scene. And then, the heroes must decide what their next approach should be now that Luigi is healthy.

Thanks for reading this chapter! Please review, follow/favorite, and I'll see in the next one!

Post-Chapter Notes:

(1): The Super Poltergust 3001, originally found in Mario & Luigi: Superstar Saga, is the upgraded version of the Poltergust 3000 Luigi used in his first mansion adventure. Designed by E. Gadd, he uses this as a vehicle to travel at high speeds. (It's not as fast as Sonic though.)

(2): Remember the Greenie who escaped Evershade Valley in Chapter 7? Yeah, I decided to give him a key role during the second half of the chapter. For this note, I let E. Gadd explain the situation of the Dark Moon and the reason why he and Colombo were unchanged from Edge's ambush. (This is unconfirmed; I made up this theory.)

(3): I took this gag from one of the Greenies during the first mission in Luigi's Mansion: Dark Moon. After being revealed from a shower, the Greenie got spooked and 'bumped' into the wall as a joke.

(4): Just like I did with the Polterpup, I gave the Greenie ghost a name to distinguish him.

(5): In Dark Moon, the professor may have accidentally admitted that he sold King Boo's original painting at a garage sale. If that's the case, it led to Luigi's second ghost hunting quest. Oh, E. Gadd…

(6): Also seen in the game, the cleaning mechanism was utilized to purify the Dark Moon pieces since they were tarnished with dark energy after being broken. It didn't have an official name so I gave it one.