Booster: SAY GOODNIGHT, YOU WORTHLESS HEROES!
The three heroes huddle together and await their death. But, just before Booster is about to hit them, an icy sword is sent flying at Booster, who is hit and sent to the ground. Booster looks around and sees the sword on the ground.
Booster: What the?
Then, the sword disappears.
Booster: What's going on here?!
Booser: I think the real question is, what are you doing to our friends?
Booster turns and sees Booser, Blade Guy, the Koopalings, and a conscious Bowser out of their jail cells. Booster then goes ballistic.
Booster: WHAT?! HOW IN THE WORLD DID YOU GET OUT OF YOUR JAIL CELLS?! BOOARIO AND BOOIGI SHOULD'VE SET THE CELLS TO GIVE OFF 1,000 JOLTS OF ELECTRICITY TO ANYONE WHO TOUCHES THEM!
Booser: Oh, they set them all right. But, you forgot about one thing. A Boo's best friend.
Booser shoots his tongue out at Booster and slaps him silly.
Booser: The tongue! I was able to get it through the bars and turn off the switch. Then, I went through the bars, grabbed the keys, and unlocked every cell.
Booster: GRRRRRRRRRRRRRRR! I'M SICK OF THIS! I AM A LEGENDARY BOO! I WILL NOT LOSE TO A BUNCH OF WIMPS LIKE YOU! IT'S TIME TO PULL OFF A FAVORITE ACT OF MINE!
Booster grabs his jester stick and pushes a button. Blue shockwaves are sent out and hit Bowser. Bowser is knocked back, but when he gets back up, he is seen with blue eyes.
Booster: WEHEHEHEHEHEHEHEHEHEHE! My favorite act! The mind control! I have the ability to control minds! Bowser, take care of these pests for me!
Bowser: As you wish, Master Booster.
Larry: Fight it!
Ludwig: Don't fall under his control!
Wendy: Daddy, please!
Morton: Come on. Dad! Fight it! Withstand it! Show resistance! Take-
Jr: Come on!
Jr. charges toward Booster in anger. But Booster just shoves him aside.
Booster: There is nothing that can break him. Bowser, destroy-
Booster looks inside the Keep and sees Iggy in his basket being carried by his charging Chain Chomp.
The Chomp charges toward Bowser and rams into him, knocking him back.
Iggy: Hehehehehe. Nobody can keep me and my Chomp behind bars.
Bowser gets up and charges toward the Chomp, picking him up and throwing him into the lava. Iggy jumps out of the basket, but the Chomp lands in the lava and flies out, all burnt, and faints.
Booster: Now, FINISH THEM!
Bowser charges toward everyone, but is stopped.
Booster: Ugggg! What now?
??????: It's time to end this, Booster.
Booster: What the?
Above everyone, King Boo appears.
King Boo: Hehehehe. Yes, we meet again, Luigi. But I'm not here for you.
He turns to Booster.
King Boo: Free Bowser and let those Koopa Brats have their Keep back.
Booster: But King Boo...
King Boo: SILENCE! Now, come back to the Mushboo Kingdom. We have no need for this place anymore. My plan is almost complete. But, I need you back at the kingdom.
Booster: ... Very well. But, just so Bowser doesn't try anything funny...
Booster shoots a beam at Bowser that puts him to sleep.
Booster: That should hold him.
King Boo and Booster disappear. Yang, Luigi, and Jr. look at each other with worried looks.
Luigi: Well, I guess our work is done.
Yang: I guess so.
Jr: But what I want to know is who it was that saved us?
Blade Guy: I believe I can answer that.
They turn and see Booser next to a Shy Guy.
Luigi: And you are?
Blade Guy: I am Blade Guy. I was the one who saved you. I used my icy powers to save you from that Boo's attack.
Jr: Wow, thanks.
Blade Guy: No problem. Now, my work here is done. And Booser...
He goes closer to him.
Blade Guy: (whispering) Don't tell anyone what I told you.
Booser: Got it.
Blade Guy nods and disappears.
All but Booser: O_O
Lemmy: Well, we have to repair the Keep now. Booser, thanks for saving us. I guess you are better than I thought you were back when me, you, and Luigi had to save Mario and Iggy from King Boo.
Booser: Thanks... I think.
Lemmy: Come on, Jr, we have a lot of work to do.
Jr: I can't.
Larry: Dude, why not?
Jr: Mario told me about a prophecy that involves me and Dad. Apparently, I am supposed to replace Dad.
Ludwig: ... Very well. Just tell Kamek we'll be fine on our own.
Jr: You got it!
Iggy: Well... good luck, guys.
The four of them head back to Starborn Valley.
Yang: You know, I wonder how Mario, Kamek, Mallow, and Geno are doing?
The four of them ponder this while heading back to Starborn Valley.
Mario, Kamek, Mallow, and Geno are seen walking in a forest. Kamek has his wand lit up so they can see. Everyone is very calm except Mallow, who is complaining.
Mallow: Of all the forests in the kingdom, it HAD to be the Forest Maze! Why couldn't be Forever Forest or something?
Mario: Please stop, Mallow. It's the Forest Maze, so what? It's not like we don't know anything about this place.
Kamek: The readings on my wand say that the Crystal Heart is only a little further.
Mario: See? We'll be outta here in no time.
The four of them see a clearing up ahead and rush for it. When they make it, they end up in a big clearing.
Geno: Well, I surely don't remember this part of the Forest Maze.
Mario: Yeah. Three other paths should be here. Where are we?
From behind Mallow, a spiky vine with a Piranha Bud taps him on the shoulder. He turns around and the vine is gone.
Mallow: That's odd.
Mallow: I felt someone tap me.
Geno: That's silly. There is no one else here besides...
Then, a blast from Kamek's wand heads for Geno. He ducks.
Geno: Hey! What was that for?!
Kamek: I just saved you.
Kamek points behind him. Geno turns and sees a Piranha Plant vine on the ground.
Geno: ... Thanks. Sorry about snapping at you.
Kamek: Eh, I've had worse. Try Bowser yelling at you for failing to notice a shell waxing that is VERY hard to notice.
Geno: Yeah, that would be worse.
Mario: Okay, we get it. The point is, we are not alone.
Then, two Piranha Plant vines appear behind them. Only this time, they have fully grown Piranha heads on them.
Mallow: MARIO! LOOK OUT!
Mario turns and sees the two heads readying to attack. He jumps out of the way. The heads go back into the bushes.
Mario: What's going on here?!
Then, stomping is heard. Mario and Co. look around the area and can't figure out where the stomping is coming from. From the bushes, a giant, green, spider-like leg appears. Then another appears. A large, green, round body appears with one spiky vine with a Piranha Plant bulb on each side acting as hands, as well as four more legs. Three heads with long, spiky necks appear. On the left, there is a blue-headed Piranha Plant. In the middle is a red-headed Piranha Plant. To the right is a yellow-headed Piranha Plant.
Mario: Wh-wh-what is that?
Mallow: I don't know. But I'm... pretty scared.
Kamek aims his wand at the beast. A blue ray comes out, but it only scans the beast. Kamek then examines the readings from his wand.
Kamek: According to my readings, this is a very rare and evil beast. It is known as... The Elemental Piranha.
Geno: Why is that?
Kamek: The Elemental Piranha is a very rare plant. There are only seven in existence. One of them must've made a home in this area. It is called the Elemental Piranha because the three heads represent special elements. The yellow one represents electricity. The blue one represents ice. And the red one represents fire.
Mallow: Well, there are going to only be six in existence now!
Red Head: You will perish-
Blue Head: -for entering this part of-
Yellow Head: -the Forest Maze!
Mario: It talks?!
Yellow Head: Of course we-
Red Head: -can talk. It's all thanks-
Blue Head: -to this heart of crystal we found!
The Red head starts coughing really hard. He then hacks up a purple Crystal Heart and holds it in one of the vines.
Blue Head: We found it-
Yellow Head: -the other day sitting-
Red Head: -right here in the center of this area.
Yellow Head: And now-
Red Head: -we will punish you-
Blue Head: -for trespassing!
The Red Head swallows the Crystal Heart and the three heads roar.
BOSS BATTLE: Elemental Piranha
The Elemental Piranha starts rushing toward the heroes, shooting fireballs. The four of them leap over the fireballs. Mario grabs his hammer and starts whacking the Red head. Kamek sends a fire spell at the Blue head, but the Blue head counterattacks by using his icy breath to weaken it, which works, preventing damage. Mallow performs Star Rain on the Yellow head, but the Yellow head quickly shoots small balls of electricity that burst when making impact with the stars. No damage is done. The Red head then takes control of one of the vines and hits Mario off. Mario is sent to the ground, hard. Mallow performs HP Rain to restore Mario. Mario gets back up.
Mario: This is insane. How can we beat someone with three heads?
Kamek: Three heads...! Thatís it! Guys, we have to confuse them.
Mario: What do you mean?
Kamek: I mean that we have to get them to attack each other. While doing that, Geno can use a Geno Flash.
Mallow: I like it.
Geno: Me too.
Mario: Then letís do it!
Mario rushes over to the side of the yellow head and tries to get the Red Headís attention.
Mario: Hey, Red Head! Bet you canít hit me!
The Red Head shoots fire breath at Mario, but hits the Yellow Head in the process.
Yellow Head: YEEEEOUCH!
Red Head: Whoops.
Mallow jumps on the Red head and gets the Blue headís attention.
Mallow: Come on, buddy. You couldn't hit me even if I wasn't trying!
The Blue head fires an icy breath at Mallow. He jumps out of the way and hits the Red head instead, and it gets angry.
Red Head: HEY!
Blue Head: Sorry.
Kamek jumps on the Blue head and gets the Yellow headís attention.
Kamek: You couldn't hit the backside of Bowser even if you tried!
The Yellow head gets angry and takes control of the vine on the left side and tries to hammer Kamek, who teleports away. So he hits the Blue head instead.
Blue Head: Why you!
Yellow: Uh... I didn't mean to?
The three heads start attacking each other with fire, ice, and electricity.
Mario: Geno, NOW!
Geno unleashes the power of Geno Flash on the Elemental Piranha. The flash explodes on the heads, causing massive damage.
Geno: Perfect shot... HUH?!
When the smoke clears, the Elemental Piranha is seen with a barrier.
Kamek: My wandís readings are off the charts. The readings say that this is the power of the Crystal Heart they have.
Red Head: Too bad. We almost-
Blue Head: -fell for your-
Yellow Head: -plan. That is-
Blue Head: -until the barrier was-
Red Head: -summoned. We realized that-
Blue Head: -you made us hurt-
Yellow Head: -ourselves. So now-
Blue Head: -we must-
Red Head: -finish you!
The Red head starts coughing again. He hacks up the Crystal Heart and activates its power. The Elemental Piranha obtains more power. The three heads are engulfed in fire, ice, and electricity. The Red head has fire on his head that is over 100 degrees and would burn you to a crisp. The Blue head has an icy mist that is below -100 degrees and would cause you to freeze if you touched it. The Yellow head has sparks flying off him that would cause 1,000 volts of electricity.
Red Head: Try to-
Blue Head: -defeat us-
Yellow Head: -NOW!
The Red head shoots large fireballs at the heroes. Mallow jumps in and performs Snowy to weaken the fireballs' power. Unfortunately, the fireball had so much power that it breaks through Snowy and hits the heroes, almost causing third-degree burn to Geno. Mallow performs another HP Rain and Geno is fully healed. The Yellow head fires large bolts of electricity at the heroes. Kamek pulls up a barrier to block the attack.
Kamek: We have to think of something fast! I don't know how much longer I can hold this up!
Mario: Okay, we really need a new tactic. We know that they have three heads, of fire, ice, and electricity. But they have no similar weaknesses.
Geno: We are looking at this wrong. They might have elements, but they are still the one true thing they are.
Mallow: ...! Plants!
Geno: Exactly. So, we need a powerful wind attack and we can take it out.
Mallow: I have been working on one. I call it hurricane. But I've only used it once, and that was way back in Barrel Volcano against Czar Dragon.
Mario: Can you pull it off?
Mallow: I think I can.
Kamek: Good, now... GO FOR IT!
Mallow jumps up and performs his new ultimate attack, Hurricane. Mallow summons a giant rain storm, then a tornado forms and merges with the rain, making a hurricane. He sends it toward Elemental Piranha. But the Blue head inhales, then exhales a giant, icy tornado to counterattack. The Blue headís tornado makes it through and heads for the heroes.
Mario: What are we going to do now?
Geno: Geno BOOST!
Geno uses his stat raising move on Mallow, who feels a lot more power burning in him. He performs Hurricane one more time and this time, it is bigger and has a lot more power. The Hurricane breaks through the icy tornado and heads for the Elemental Piranha.
All Three Heads: NOOOOOOOOOOOOOOOOOOOOOO!
The hurricane engulfs them and they begin taking a ton of damage. When the hurricane ends, the Elemental Piranha shrinks back to its regular size and spits up the Crystal Heart. Mario goes up to the Heart and grabs it.
Geno: Thatís great that we got the Heart, but is that Elemental Piranha going to be okay?
Kamek: He should be, at least I think so.
Mallow: Well, it really doesn't matter right now. What matters is that we only need four more Hearts. Letís get back to Starborn Valley!
Kamek: All right, I'll just teleport us to the Koopa Cruiser and we can leave.
Kamek does so and the four of them head back to Starborn Valley.
Back in the Mushboo Kingdom, King Boo, Princess Boo, the Boo Bros, Prof. Boo, Boolossus, and Booster are all in the throne room, discussing the Crystal Heart dilemma.
Prof. Boo: How come we don't look for the last four Hearts together? You can send four minions after them.
King Boo: I can't. That stupid crystal ball Booario and Booigi got from the Star Spirits only locates one at a time. If a Crystal Heart is found and obtained, then it will locate the next one.
Booario: What if you combine your powers with the princess? You might be able to look deeper into the crystal ball.
King Boo: Hmmm... I like it. Come, my Princess, let us combine our powers to locate the last few Crystal Hearts.
Princess Boo nods and approaches the crystal ball with King Boo. They both put their stubs on it and four bubbles appear from the crystal ball.
Booigi: It's working!
The first bubble shows Dimble Woods. The second bubble shows Bean Valley. The third bubble reveals Crystal Palace. And the fourth bubble Boo Woods, leaving everyone shocked.
Boolossus: ... Are you serious?
Booster: One of the Hearts was located in Boo Woods?
Prof. Boo: Well... this is... weird.
King Boo: Excellent! With the location of these Hearts and the Heart we have, that gives us five! Meaning we only need the last four from those stupid Mario Bros! Now, Boolossus, Booario, Booigi, and Booster! I want you to go and fetch these Hearts. Boolossus, Dimble Woods. Booario, Bean Valley. Booigi, Crystal Palace. And Booster, Boo Woods.
Boolossus: Sir, yes sir!
The four of them leave, and King Boo, Prof. Boo, and Princess Boo are left.
King Boo: Now, all we need is to bring the Mario Bros. here. But how are we going to do that?
Prof. Boo: Sir, might I suggest that we just let them find out that we have the rest of the Crystal Hearts?
King Boo: No, that will take too long.
Princess Boo: What if Prof. Boo makes a machine that can deliver a message to the Mario Bros?
King Boo: I like it!
Prof. Boo: I'll get to work on it right now.
He rushes off and starts building the machine.
King Boo: Excellent.
Moments later, Booigi comes back with a Crystal Heart.
King Boo: Back so soon? You were assigned Crystal Palace. How did you find it so fast?
Booigi: Eh, I just went though the walls of the whole place and stole the Heart from Crystal King.
King Boo: Nice.
Then, Boolossus appears.
King Boo: How did it go?
Boolossus: I just found it laying on the ground at the Wiggler Farm.
King Boo: Well?
Booario: Beat up Shy Away for it.
Finally, Booster comes back.
Booster: You'll never believe where it was. I found it at Boo Tower.
King Boo: Impossible! I was there during the Star Portal incident and found no Heart!
Booster: It was somewhere at the top of the tower.
King Bo: Oh, well, I was never in that area. But, now that we have collected the Hearts, we wait for Prof. Boo.
He comes rushing in.
Prof. Boo: It is ready!
King Boo: Perfect. Now, all I need to do is write a letter and...
Prof. Boo: Oh, it is a recording messenger, so no letters required.
King Boo: Oh. Record something telling the Mario Bros. that we have the last four remaining Crystal Hearts, and to come if they dare.
Prof. Boo: Very well, sir.
He rushes off.
King Boo: Right, now. Get to your battle stations!
Boo Bros, Booster, and Boolossus: Yes sir!
They drop the Hearts and head to their battle stations.
King Boo: Hehehehehehehe. Come, Mario Bros... if you DARE!
The Koopa Cruiser lands in Starborn Valley and the four heroes head for Merleís house. When they enter, they see Luigi, Jr, Booser, and Yang.
Mario: We got the Heart.
Yang: And we saved Booser.
Merlon: Perfect, now we just need to locate the next Crystal Heart.
Just as Merlon is about to locate the next Heart, a Boo-like robot appears and talks in the voice of Prof. Boo.
Robot Boo: Mario Bros, King Boo has collected all the remaining Hearts. If you want those and want to save your beloved Princess Peach, come and take on King Boo himself, if you dare!
The robot Boo leaves.
Mario: Oh no.
Merle: What are you going to do now?
Luigi: We have to go to the Mushboo Kingdom Castle and get those Hearts!
Mallow: You can't be serious!
Luigi: I am serious. Me and Booser have dealt with King Boo before. If me and him can take him, so can you guys!
Geno: Luigi's right. We can take him!
Jr: I'm with Geno. Letís go and take those Hearts back!
Luigi nods and Booser nods back to Luigi.
Mario: Thanks for those words of wisdom, Luigi. Now letís go and get the Hearts and save the Princess!
Kamek: I'll take you there. Everyone on the Cruiser!
Everyone heads for the Cruiser, but Luigi and Booser are stopped by Merlon.
Merlon: Luigi, these came in the mail for you not too long ago. I didn't want to give it to you until now.
Luigi takes the package and opens it. Inside is the one thing that will defeat King Boo.
Luigi: Tell E. Gadd I said thanks. Letís go, Booser.