I do not own Pokémon at all. Also, the idea is not original per se. A YouTuber's video gave me ideas. I also talked to said YouTuber personally, and he helped out. His name is EliteMJ. Go look him up on YouTube, his videos are very well-made.
Before the Journey began for Aaron, Daphne, and Franklin, the Regions found themselves at war. Those of the forces following Ash Ketchum; gym Leaders, coordinators, elite 4 members, and Champions fought against those of the Evil teams; Team Rocket, Team Magma, Team Aqua, Team Galactic, Team Plasma, Team Flare, and the Aether Foundation that didn't follow Lusamine.
The War ravaged all across the Regions, and all Pokémon were involved, even wild Pokémon. Near Cerulean City was another battle in the war, where Misty defended her home against Team Rocket Grunts. She had her Water-type Pokémon use Water-type moves like Hydro Pump, Aqua Jet,or Hydro Cannon. Misty had her Starmie use Rapid Spin to hit grunts away while her Clawitzer covered the Mysterious Pokémon with powerful Hydro Cannons.
"KEEP THEM BACK! WE NEED TIME FOR THE CIVILIANS TO GET TO SAFETY!" Misty shouted as she looked at Cerulean. Somewhere in there were her daughter and Eevee, and she knew that she needed to buy time for them. That was when she heard an explosion and looked. A Houndoom was standing over her Clawitzer, with Team Rocket Admin Archer standing behind it, with an evil smirk on his face.
"Archer… STARMIE! RAPID SPIN!" Misty shouted as Starmie spun past her towards Houndoom, but Archer told his Houndoom to use Bite; it did, and it broke Starmie's core. It shook the pokémon before throwing it to the side. Misty was shocked and sent out her Gyarados and had it use Hydro Cannon, getting a direct hit. She then ran over to Clawitzer to check on him. Clawitzer was okay, and she recalled him before checking on Starmie, which was when she saw that Starmie was gone. She teared up and held her fallen pokémon close.
"FLAMETHROWER HOUNDOOM! ROAST HER ALIVE"! Archer shouted as Houndoom shot a powerful Flamethrower at Misty. She braced to get hit, but was scooped up by a Pokémon. She looked down and saw a White Pokémon with wings. She recognized it as a Swanna and heard someone say, "Thought you could use a wing!" She turned and saw Skyla, the Flying-type Gym Leader from Unova, flying on another Swanna. Misty smiled and thanked her before the two landed on the ground, where Misty's Gyarados got to them.
"What's the situation?" Misty asked Skyla. Skyla told her that Cerulean City was nearly fully evacuated before getting hit by a Flamethrower by Archer's Houndoom. Misty shouted to Skyla before having Swanna use Bubble Beam on Houndoom. The Houndoom got sent backwards as Misty ran over to Skyla.
"I'm… ok. Listen, when we were up there…. We saw Ash… he's surrounded. Take Swanna… get there and save him." Skyla said as she handed Misty the spare Pokéball for the Swanna that saved her. Misty looked and nodded before getting on Swanna's back and taking off. Skyla smiled as she and Swanna slowly stood and looked at the Team Rocket grunts. Skyla cracked her knuckles and said, "We'll defend Cerulean City to our last breath."
Back with Misty, she had Swanna use Bubble Beam across the enemy Pokémon surrounding Ash. Misty had Swanna land near Ash and ran to him. Ash smiled and thanked her for the help. Misty nodded her head and asked him what the situation was.
"Right now we've got reports that one of the Rocket Admins has a legendary under their command, think you can take them on?" Ash asked her. Misty nodded her head and looked at Swanna before shouting, "Let's go!" Swanna nodded, and they flew around. That was when Misty saw it, Regirock with Giovanni's wife controlling it. Misty had Swanna shoot another Bubble Beam near her.
"Waterflower," Ariana said as she had Regirock use Ancient Power on Swanna. The controlled Regi fired Ancient Power, and Misty had Swanna use more Bubble Beam to counteract the Ancient Power. The two moves met in the middle, but the Ancient Power powered through Swanna's Bubble Beam and got a direct hit on the White Bird Pokémon. Misty had Swanna land and recalled her before sending out Gyarados.
"Strong, Valiant, and Powerful! And now my beautiful blue sweetheart! Mega evolve!" shouted Misty as she mega evolved her Gyarados. She then said, "USE IRON TAIL!" Her Gyarados obeyed and charged at Regirock. Ariana shouted, "USE HAMMER ARM!" Regirock obeyed and charged at Gyarados, the two moves met and caused an explosion that enveloped them both. Misty shouted for her Gyarados to use Bite. He bit down, but that allowed Ariana to tell Regirock to use Hammer Arm again, and he was able to get a direct hit.
Gyarados slid backwards and shook off the damage. Misty then shouted to use waterfall, and he obeyed, but Ariana smirked as Gyarados was about to hit, he got hit by a powerful thunder. Misty looked at where the thunder came from and saw a Magnezone with Team Galactic admin Charon, who had a smirk on his face.
"THUNDER AGAIN MAGNEZONE!" But before Magnezone could unleash a second thunder, the sound of hoofs was getting closer. Charon and Magnezone looked behind them before getting sent off the hill they were on by the move Sacred Sword. That was when Keldeo, the Colt Pokémon, appeared in his Resolute form and soon joined Misty and Gyarados.
"Gym Leader Misty, I sensed you required assistance. Have your Gyarados rest, I will assist you in defeating the woman controlling Regirock. My moves are Sacred Sword, Swords Dance, Hydro Pump, and Close Combat," was what Keldeo said to Misty, who smiled and nodded her head before recalling Gyarados. She then looked at Ariana and shouted, "KELDEO! SWORDS DANCE INTO SACRED SWORD!" Keldeo obeyed and got a boost from Swords Dance before following it up with a Strike of Sacred Sword on Regirock before Ariana could even react.
"NOW CLOSE COMBAT!" she shouted. Keldeo jumped around Regirock as it got hits on the Rock Peak Pokémon. Ariana ordered it to use Hammer Arm, but Keldeo was so fast it couldn't land a hit. But that was when Keldeo struck the device Ariana was using to control Regirock, and it stopped moving. Ariana ordered Regirock to use Hammer Arm again, and it did, but against her this time.
"WHAT?! I AM YOUR MASTER! OBEY ME!" She shouted, but Regirock just used Hammer Arm on her again. Soon, a massive explosion was heard from the other side of Mount Moon. Ariana gritted her teeth as she heard about the weapon being destroyed and ordered a full retreat. Misty saw the Enemy pulling back as she walked up to Regirock as it sat on the ground. Ash came over and used his Aura to calm Regirock as it was distressed. As Ash tended to Regirock with help from Brock, who had just shown up, Misty went back to where she last saw Skyla. Getting there, she saw Skyla and her Swanna on the ground, motionless.
"No… no no no NO! SKYLA!" Misty shouted as she ran to the Unova Gym leader. Upon reaching the falling Gym leader, Misty tried everything to wake her up, but nothing worked. Skyla had given her life to defend Cerulean City. That was when Keldeo joined her and said, "Skyla… I knew of her exploits in Unova… She was a hard gym leader. She will be missed." Misty looked at Keldeo and then felt someone behind her. She and Keldeo looked, and there stood Ash, his face filled with horror as he saw Skyla's body.
"No… not another one," he said as he walked over and knelt before putting his hand on her head, giving her a small prayer. Afterwards, Misty looked at the Pokéball of the Swanna Skyla had given to her as Ash walked over after talking to the other champions. Sitting next to his oldest female companion, he put a hand on her shoulder. He told her, "I know you two just became friends, Misty… no amount of words will convey what I know…"
"Just shut up!" Misty shouted as she began crying, "Talking about her won't do us any good." She then hugged Ash, and Ash hugged her back. Soon, Keldeo rejoined them and asked Misty, "Gym Leader Misty, if you would have me, I would be honored to call you my trainer." Misty blinked before looking at Ash and saw him nodding his head. She nodded back and held up an empty Pokéball. Keldeo tapped it and went inside it. After three shakes and a ding, Keldeo was caught.
Later, Misty walked into her home and saw her daughter run up to her and hug her. It had been too close to home, and she was glad her daughter was ok before showing Keldeo to a young Daphne. The two got along well, and that made Misty happy.
In the present, Misty watched Keldeo sleep near her youngest child as Gary walked up to her and kissed her cheek. He then looked at Keldeo too and said, "He's taken to our son quite well." Misty nodded her head and agreed with her husband. Soo,n Gary said that it was almost time for her gym battle with Aaron.
"I know, and just because he's the kid of Ash Ketchum, I'm not gonna hold anything back," Misty said as she looked at the Pokéballs on the shelf; one was her Starmie's Pokéball, the second was the Pokéball of the Swanna Skyla gave her, and the third was Keldeo's Pokéball. Gary smiled and told her that she was a good Gym leader. Misty nodded her head before grabbing two Pokéballs and walking out to face Aaron in his Cerulean Gym Battle.