Cassidy and Butch in Sinnoh

Today the gang had come to a desert; they needed to cross it to get to Veilstone City. Because of all the sand Ash called the desert a great place to train Hippopotas and his new Gligar. A few days ago the gang came to a city which had trouble with a swarm of Gligar and their leader Gliscor, the evolved form of Gligar. The swarm had been blown into the city because of a storm and the swarm kept taking fruit from shops. But the gang helped Officer Jenny and Nurse Joy get the swarm back to the forest. In the midst of that excitement Ash caught a Gligar and Paul, who was visiting the city captured the Gliscor; he found it worthy for his team. 
Ash sent out his Hippopotas and Gligar.
"Okay you two." He said. "We are going to train in the desert today."
Hippopotas liked that because he liked sand.
Gligar was happy too; it was a female and she liked Ash a lot.
"Before we do start training I have something special for you two." Ash said.
He took two TM's out of his backpack.
"Hey I've seen those in shops." Dawn said. "But they are expensive."
"No need to worry Dawn." Ash replied. "I've saved up a lot to get some TM's." 
"Which ones do you have?" Brock asked. 
Ash had the TM's for Water Pulse and Sandstorm. Hippopotas could learn both moves and Gligar could learn Sandstorm. Ash returned the two to their Poke Balls, placed the TM's on the Poke Balls and then released them. 
"Okay now let's see your moves." Ash said.
Hippopotas had learned new moves ever since Ash caught him; he learned Roar, Protect, Double Team, Hidden Power, Mud Slap and Strength in addition to Water Pulse and Sandstorm. As for Gligar; she knew Poison Sting, Sand Attack, Harden, Quick Attack, Steel Wing, X-Scissor and the egg moves Metal Claw and Cross Poison alongside Sandstorm. 
"Okay, see those rocks in the sand?" Ash pointed to the rocks. "Strike them with your Metal Claw Gligar and Hippopotas use Strength." 
Hippopotas and Gligar got to work right away. Gligar was the type of Pokemon who wanted to please her trainer and earn his attention and approval. It wasn't long before Gligar started to smash up rocks with Metal Claw and Hippopotas started to tackle rocks around. 
"Wow Brock." Dawn said. "Ash's Hippopotas has gotten stronger and Gligar sure isn't backing down even though it's new."
"Well Gligar loves Ash." Brock said. "So she's determined to gain Ash's approval." 
Dawn thought that was amusing.
Suddenly there was a rumbling noise coming from under the sand. 
"What's going on?" Dawn asked, worried.
Before her question could be answered, some big hippo-like Pokemon came out of the sand. 
"They're Hippowdon." Brock said.
Dawn looked Hippowdon up on her Pokedex.
"Hippowdon, the Heavyweight Pokemon and the evolved form of Hippopotas. It blasts internally stored sand from ports on it's body to create a towering twister for attack."
"They probably live in the desert." Brock assumed.
Suddenly a giant robot came towards the Hippowdon and hit them with rockets.
"What the hell?!" Ash shouted.
Just then, to the gang's surprise, Cassidy and Butch came out of the robot.
"Oh great, it's you two!" Ash shouted.
"Well, well, well if it isn't the brats." Cassidy said.
"Haven't seen you in a while." Butch added.
"Who are these two?" Dawn asked Brock. 
She had never seen them before.
"Cassidy and Butch are members of Team Rocket." Brock explained.
Cassidy looked at the Hippowdon.
"They would be good for the boss." She declared.
"You're not taking these Pokemon anywhere!" Ash shouted.
"Get ready." He ordered Pikachu, Hippopotas and Gligar. 
Cassidy and Butch sent out all their Pokemon to battle and they had new ones; Cassidy had a Charizard and Butch had an Aggron.
"Let's help Ash." Brock said.
Dawn and Tomo agreed as Team Rocket had too many Pokemon for Ash to deal with alone. But before anyone did anything the Hippowdon attacked the robot with Stone Edge and then they used Dig to get away.
"Grr, the Hippowdon got away." Cassidy growled. "Come on Butch, let's go after them."
Butch turned to the gang.
"You brats better not get in our way again; we will show no mercy next time." He said.
He and Cassidy returned their Pokemon and left in their robot.
"They're gone." Ash said.
"Where'd they go?" Tomo asked.
Cassidy and Butch were away in their robot. 
"I can't believe we actually ran into the brats here." Cassidy said.
"Well what do you expect." Butch said. "They travel all over the place."
Suddenly a phone in the robot rang. It was Dr. Namba. 
"Have you found the Hippowdon?" He asked them.
He wanted a Hippowdon to research it for it's sand; what for though was a mystery.
"We found the Hippowdon and are pursuing them now." Cassidy replied.
"Do not fail me!" Dr. Namba shouted.
Then the phone call ended.
"I really don't understand that old man sometimes." Cassidy said. "I mean, what's so special about a Hippowdon's sand?"
"Ah when that guy has something on his mind, who knows what he's thinking." Butch said.
The duo resumed their search for Hippowdon.
Meanwhile...
The gang had gotten over their surprise.
"So those two are members of Team Rocket?" Dawn asked.
"Giovanni has hundreds of agents working for him." Ash answered. "What are they doing in Sinnoh, anyway?"
"I don't know, but we need to find the Hippowdon before Cassidy and Butch do." Brock said. "Who knows what they will do to them."
"Yes, but how will we find them?" Tomo asked. "The Hippowdon dug into the sand and this desert is full of it."
"Gligar can help us with this." Brock said. "She can use her sound waves to help us find the Hippowdon."
"Good idea. Gligar, can you try to locate the Hippowdon for us please?" Ash asked.
Gligar was eager to please Ash and she took off into the sky and used her sound waves to try and locate the Hippowdon.
"I hope Gligar can find them." Dawn said.
After Dawn said that, Gligar cried out in excitement.
"You found them, Gligar?" Ash asked.
Gligar nodded yes.
"That's great, thank you." Ash said.
Gligar was happy to have done a good job and she flew into Ash to hug him. This was her way of showing affection to him. Ash pulled Gligar off him and everyone ran off to find the Hippowdon.
The gang did find the Hippowdon and they were happy to see that they were okay. Cassidy and Butch then appeared in their robot.
"Let's stop them!" Ash shouted.
He called out his Zangoose, Staravia and Chimchar to help Pikachu, Gligar and Hippopotas. Dawn sent out Piplup, Wormadam, Ariados, Pachirisu, Clefairy and Drifloon to help. Brock called out his Sudowoodo, Probopass, Croagunk, Happiny and Nuzleaf. Tomo sent out Electivire, Chimchar, Shellos, Growlithe, Sceptile and Tauros to battle.
"Everyone, protect the Hippowdon!" Dawn shouted.
Cassidy and Butch noticed the Pokemon and sent out all their Pokemon to fight back.
"The Pokemon can distract the brats while we get the Hippowdon." Butch suggested. 
"Great idea." Cassidy said.
The battle was on.
While the Pokemon were fighting, Cassidy and Butch proceeded to capture the Hippowdon with their robot. They fired rockets at them to weaken them first. Ash's Hippopotas noticed this and ran toward the robot to stop it.
"Look Cass." Butch said. "That Hippopotas is coming toward us."
Cassidy smirked.
"That puny thing couldn't do any harm to us." She chuckled. "We are a lot stronger than it."
As soon as Hippopotas got close to the robot, Cassidy used the robot's arm to knock it away. The gang noticed what was happening and Ash was concerned about Hippopotas. Hippopotas was shaken by that, but he wasn't willing to give up and let Team Rocket take the Hippowdon.
"Ha give up you little pipsqueak." Butch laughed. "You don't stand a chance against our robot."
Even though Hippopotas was small, he wasn't going to quit despite Butch's words. Hippopotas roared and then he glowed and evolved into Hippowdon. Cassidy and Butch were in trouble now. Hippowdon charged towards the robot and tackled it really hard.
"Look at Hippowdon go." Brock said. "We must help him at once."
The others agreed and they commanded their Pokemon to attack. Together they all defeated Team Rocket's Raticate, Houndour, Sableye, Tentacruel, Granbull, Charizard, Primeape, Hitmontop, Mightyena, Cloyster, Shuckle and Aggron. Ash's Hippowdon and the wild Hippowdon, who had seen everything, charged at the robot together. Cassidy and Butch were really in trouble now. 
"Hippowdon, use Hyper Beam." Ash said.
He had just found out on the Pokedex that Hippowdon knew Hyper Beam now. Ash's Hippowdon got ready to use Hyper Beam and so did the wild Hippowdon. Cassidy and Butch tried to escape with their Pokemon, but it was too late. The Hyper Beam attacks hit the robot, sending Team Rocket and their Pokemon flying.
The gang was happy Cassidy and Butch were gone. The wild Hippowdon were grateful for the gang's help.
"What a day." Ash sighed. "I hope we don't see Cassidy and Butch again."
"Me too." Brock added.
Having Jessie, James and Meowth around was bad enough. So with the trouble over, the gang spent some more time watching the wild Hippowdon before they left.
All the while, Cassidy and Butch decided to find a Hippopotas so Dr. Namba could evolve it for research; that was a easier solution then capturing a Hippowdon. They immediately set off for Kanto.