Venusaur vs Torterra

One day...
Cynthia and Aaron were having their battle. Cynthia sent out her Garchomp while Aaron sent out his Drapion. Millions of people were watching at the stadium and on television. In a Pokemon Center Paul was watching the battle on TV. Then, the gang entered the Pokemon Center just in time to watch the battle. Paul noticed their arrival but wasn't interested in them at the moment. Ash noticed Paul, but he was only interested in the battle. In the end it was down to Gastrodon and Beautifly. Garchomp had been defeated, but in the process Aaron's Drapion, Vespiquen, Heracross, Yanmega and Scizor had fainted. Beautifly was Aaron's last Pokemon.
"Beautifly, Solar Beam." Aaron ordered.
Gastrodon used Stone Edge to defend itself against the attack. Then Stone Edge hit Beautifly. It fainted and Aaron lost the battle. Cynthia was keeping her title as Sinnoh Champion.
Team Rocket watched the battle too. They had disguised themselves as Pokemon Center employees. 
"Well, well, well Aaron was defeated by Cynthia, huh?" James smirked.
"His Pokemon didn't stand a chance." Jessie smirked as well.
"I thank the champion for teaching him a lesson for us." Meowth also smirked. 
He remembered Aaron defeating them when they first met.
"So even Aaron can't defeat Cynthia?" Ash noted. 
"Especially after all that training and being excited having his Beautifly back." Dawn said.
"I believe Cynthia won't be losing her title for a long time." Brock said.
"Somehow I think even the other Pokemon champions would have a hard time beating her." Ash said.
Just then Paul appeared.
"Paul." Ash said.
He didn't say a word and walked away.
"What's up with him this time?" Tomo asked.
"No idea." Ash said.
"As he was watching the battle I wonder if he remembers the battle he had with Cynthia." Brock said.
"Wouldn't surprise me really." Ash said. "Especially since Garchomp didn't break a sweat against all of Paul's Pokemon."
The others agreed.
A moment later the gang went outside to train. Ash's Turtwig was running around like crazy.
"What's wrong with Turtwig?" Dawn asked.
"Ah, he's trying to make myself stronger to be like my Venusaur." Ash said. "You see, my Venusaur is the peacemaker at Prof. Oak's lab as well as one of my strongest Pokemon. Turtwig wants to be like Venusaur."
"Oh I see." Dawn said. "Hey Ash, can I see your Venusaur? I'd like to see it myself."
"Sure I'll bring him here right away." Ash said.
Ash got out his Pokedex and swapped his Gliscor for Venusaur. Then he released Venusaur from his Poke Ball.
"Hi Venusaur." Ash said, giving him a hug.
Venusaur was happy to see him.
"Oh wow Ash, your Venusaur is amazing." Dawn said.
What he didn't know was that Paul had been watching him and saw Venusaur. Brock noticed Paul and walked over to him.
"That Venusaur." Paul said.
"Ash caught Venusaur when it was a Bulbasaur during his journey through Kanto." Brock said.
Paul stared at Venusaur some more and walked over to it. Ash and Dawn were fussing when he approached them.
"Paul, what's up?" Dawn asked.
He ignored her.
"Your Venusaur." He said to Ash. "I take it it's strong, right?" 
"Yes Venusaur is strong thank you." Ash said. "And I will prove it in a Pokemon battle."
Venusaur growled.
"Very well." Paul said. "I'd like to see how your Venusaur does against my Torterra."
"Agreed." Ash said.
It wasn't long until Ash and Paul were in position and Venusaur and Torterra were ready to fight.
"Why am I not surprised Ash and Paul would battle each other when they met up again." Dawn said.
Piplup chirped in agreement.
"Paul's going to be sorry this time." Tomo said. "Venusaur's no pushover."
"Yes, especially since it's a grass/poison type." Brock said.
Ash's Turtwig wanted to watch the battle so he stood on the sideline. Unbeknownst to them, Jessie, James and Meowth were spying on everyone.
"Well, well it seems a Pokemon battle is about to begin." James said.
"Let's watch it." Meowth said, eager to know what would happen. 
Jessie and James agreed with the idea.
"Hyper Beam." Paul told Torterra.
"Venusaur, Protect." Ash ordered.
"Venusaur, use Power Whip." He said.
Venusaur attacked Torterra with Power Whip and it just stood there taking the hit.
"Humph not bad I guess." Paul said, rudely. "Torterra, use Crunch."
Torterra went towards Venusaur to bite down on it.
"Venusaur tackle it." Ash said.
Venusaur and Torterra collided with each other; Venusaur trying to push Torterra with Torterra trying to push Venusaur back.
"Venusaur and Torterra are both strong." Brock said. 
"Venusaur, use Sludge Bomb." Ash said.
Sludge Bomb hit Torterra.
At that moment Paul called out, "Enough."
The battle was stopped.
"It seems your Venusaur is indeed a worthy Pokemon."
"Like I said when we first met Paul, don't underestimate me or my Pokemon." Ash said. 
Pikachu, Turtwig and Venusaur called out in agreement. Paul just huffed, returned his Torterra and walked back into the Pokemon Center. Ash returned his Venusaur to have him checked out in the Pokemon Center too.
Later that day
The gang spent more time with Venusaur. 
"Your Venusaur was magnificent against Torterra, Ash." Dawn told him.
"It certainly showed Paul a thing or two." Tomo said.
Turtwig was having a battle with Venusaur itself; not a serious one, more of a training battle. Turtwig tackled Venusaur, but Venusaur pushed him back with his head.
"Excuse me." Dawn said. "But Turtwig will hurt himself if he does that."
"No need to worry Dawn." Ash reassured her. "Venusaur is the peace keeper at the lab so if Turtwig does too much Venusaur will stop him."
"Oh okay." Dawn nodded in understanding.
Suddenly, after being thrown back from Venusaur, Turtwig started to glow. He grew into a big turtle-like Pokemon, with two big bushes on it's shell.
"Wow, Turtwig evolved!" Dawn gasped.
Ash happily looked at the Pokemon on his Pokedex.
"Grotle, the Grove Pokemon and the evolved form of Turtwig. It lives along water in forests. In the daytime, it leaves the forest to sunbathe it's treed shell."
Grotle wanted to charge at Venusaur with it's new strength, but he noticed he couldn't run as fast as he did as Turtwig. The gang noticed this too. Venusaur fired razor sharp leaves at Grotle. Grotle tried to dodge it, but he couldn't do it like he did as Turtwig.
"Uh oh." Tomo said after witnessing everything. "Grotle's one of those Pokemon that can't move really fast because they're heavy."
"You're right, Tomo." Brock nodded. "Grotle has a big, heavy shell now and that's why it moves rather slowly."
Ash stepped forward towards his two grass type Pokemon. 
"I'm sorry, Grotle." He apologized, rubbing his head. "But I'm afraid you can't move quickly in this new form. Venusaur, I'll need you to teach Grotle how to attack like you; using attacks to defend itself and how to use his head to push enemies back like you do."
Venusaur nodded in understanding.
Ash decided to show Grotle what Venusaur does in battle with Pikachu and Chimchar.
"Okay Grotle, pay close attention to this." He said.
Grotle nodded in agreement.
"First off, Chimchar use Flamethrower." Chimchar blew a stream of orange fire while Venusaur used Protect to defend himself.
"Grotle, you know Protect as well so normally you would have to use it to defend yourself, but watch this. Chimchar, Flame Wheel." Chimchar charged head on at Venusaur with Flame Wheel, but Venusaur used his head to push Chimchar back.
"You see that Grotle, even though you're not as fast you're still strong, so you can use your strength to push the enemy back when they charge at you and you still have your attacks to rely on to counter your opponent's attacks." Ash had Pikachu use Thunderbolt, but Venusaur countered it with Energy Ball.
This really taught Grotle a lot.
Next it was Grotle's turn.
"Okay Grotle, let's see how good Withdraw is." Ash said.
Grotle laid down on the ground, tucked his legs in and kept his head down as he glowed green when using Withdraw. Chimchar charged forward with Scratch but Grotle didn't take much damage thanks to Withdraw. Even when Chimchar used Flamethrower, Grotle was still protected by Withdraw.
"That's good Grotle. Okay, now let's see how you push your enemy back with your head like Venusaur did."
Chimchar charged towards Grotle with Flame Wheel and Grotle managed to push Chimchar back with his head.
"Great work Grotle. Now heal yourself with Synthesis." Grotle used Synthesis and recovered.
"Okay, that's enough now." Ash finally said. "Venusaur, I think it's time I returned you to the lab. I get the feeling that the lab is in turmoil again. Grotle, you'll go to the lab as well to aid in the peace keeping efforts alongside Venusaur and learn from him some more."
The two grass type Pokemon nodded in understanding. Ash returned them to their Poke Balls, then sent them back to the lab.
"I have to say." Dawn said. "I know you boys told me before that older Pokemon make very good teachers for younger Pokemon. But that sure was a lot of teaching."
"Well Dawn, there will be a time when your Pokemon will become teachers for your new Pokemon in the future." Brock stated.
"I must ask Ash." Dawn said. "What did you mean when you said the lab will be in turmoil again?"
"Well Dawn." Ash began. "The Pokemon at the ranch quarrel over everything; property, food, etc. So there are times Venusaur has to get involved and stop the quarreling." 
"Oh I see, that sounds scary." Dawn said.
"Trust me, it is." Ash responded.
Unbeknownst to the gang, Torterra had been watching Venusaur and Grotle the whole time. It considered Venusaur to be a worthy rival and felt Grotle would be one as well.