Luigi landed on a familiar planet in the Good Egg Galaxy. Well, it was barely familiar. The house that he had once been trapped on top of was a pile of rubble, Bowser's airships clouded the open space, and there were enemies everywhere. Two Octogoombas noticed Luigi immediately, promptly firing rocks at him. He dodged both rocks and stomped on them, before looking around.
"Now, where's that launch star?" Luigi muttered to himself. It was nowhere on this side, so he stepped over the round edge into the dark underside of the planet. He leaped up the stone tower, and sure enough, there was a Luma trapped inside of a crystal. He spun around to break the crystal, freeing the Luma.
"Thank you! Now, let me return the favor. Time to…TRANSFOOOOORM!" The Luma began to spin around rapidly before transforming into the launch star Luigi needed.
"Thanks, Luma." He said before launching himself from the star. He flew through space before landing on one of the airships. A Goomba charged at him as soon as he landed, but Luigi simply jumped on it without a second thought. A switch towards the back of the ship lowered a bridge to the next one, where Luigi took out two more Goombas. There was a Magikoopa at the helm, but Luigi didn't defeat it. Instead, he simply leapt over and pinned it to the ground. "Where's Larry?" he sneered. The Magikoopa laughed.
"Like I would tell you! Besides, aren't you the cowardly brother? You couldn't hurt a Toad!" That did it for Luigi. He dragged the Magikoopa to the side of the airship, dangling him over the black hole below.
"Talk!" he ordered. The Magikoopa put its hands up.
"Okay, okay! Let's be reasonable…" It waved its wand, causing a launch star to appear behind Luigi. "That star will send you on the right path. Now put me down!" Luigi wanted to simply let go. This creature worked for the monster that murdered his brother. But, a deal was a deal. He dropped the Magickoopa onto the deck before jumping into the launch star without saying a word, landing on a green bean-shaped planet. The only enemy there was a Pirahna Plant, so he spun and knocked it off of its stem before a vine grew. Just as Luigi expected, the vine led straight to the next launch star. This one sent him to a red, rocky planet that had an airship orbiting it. As Luigi landed on the planet's surface, a familiar tuft of blue hair poked over the railing of the airship.
"Where's the star, Larry?" Luigi called out as Larry jumped onto the railing of the ship.
"Oh, you mean this star?" Larry laughed while pointing his wand at Luigi. Sure enough, there was a Power Star in the tip of the wand. It reminded Luigi of the one Mario told hime about that belonged to Kamella. She also had star in her wond that powered it, and it appeared that Larry had one just like it.
"Hand it over, and I won't tear that ship apart piece by piece!"
"Oh, since when did you get so brave? The last time I saw you, you were just a scaredy-cat. Second fiddle to your bro. Thank goodness Lord Bowser killed him for you, now you can have the spotlight!" That was the last straw. Luigi made a leap towards the ship, but a blast of magic from Larry's wand sent him right back to the surface. "Hey, now, let's calm down. After all, there's an old pal of Mario's that wants to say high. And, let's just say that he's had a bit of a growth spurt. Have fun, Luigi!" Larry cackled as he flew the ship far enough away that Luigi couldn't get to it. Luigi suddenly felt a rumble beneath his feet before turning around and seeing a large, leafy head in front of him. He jumped back as the large Dino Pirahna crawled out of the ground, letting out a roar that shook the entire planet. This must be the baby that Mario had told him about, except that it wasn't a baby anymore. The piranha swung its rocky tail around, forcing Luigi to dive out of the way.
"Okay, Mario. If you beat this thing, then so can I!" Luigi thought to himself. If he remembered correctly, Mario used the tail to his advantage. When the piranha took another swing, Luigi used a spinning move at just the right moment. The tail bounced back into the piranha's jaw, sending star bits everywhere as it turned red. Now it was mad, but Luigi knew its weakness. After knocking the tail back several more times, the tail suddenly snapped clean off, flying directly into Larry's ship.
"What?!" Larry shouted as he was thrown off balance. The wand flew from his hand, smashing onto the hard exterior of the planet. The piranha, now wounded, burrowed back into the depths to recover. "Not bad, Luigi. Maybe you are a suitable replacement for Mario. Catch ya later!" Larry flew his smoking airship away from the planet as Luigi picked up the star, his other hand clenched into a fist.
"Come on, buddy. Let's get you back to the observatory."