Taken in

Team Aqua?!

"Come on this way!"
Crystal kept her head down as she held the injured Ice type pokemon in her arms.  All she could do was focus on saving the pokèmon.
The pokèmon let out a small sneeze, followed by a yelp.
"Not good the poison is sinking in!" Diantha said,
"The pokèmon center is just a little bit further!" Steven said......

Now how did the three of them end up in this situation?

"Wait. Who are these guys Steven?" Crystal asked, the two where hiding behind a tree, near a clearing where multiple people in blue outfits where standing.
"There called team Aqua. A group of bad guys who steal other peoples pokèmon. And attempt to awaken the legendary pokèmon of the region" Steven explained
"Oh.." Crystal had no idea how to respond.
"They've got a pokèmon. Look"
"Its a shiny vulpix from the looks of it" Crystal explained,
"No. Look, it's tail and hair are much more fluffy like snow" Steven said
"So its Galarain?" Crystal asked
"Alolan. Yes vulpixs Alolan form can be found in galar its just rare and very uncommon"
"Vul~" The pokèmon cried in fear.
"The poor thing" Crystal mumbled,
'I can do something is just that. Would he stop me?' Crystal looked at Steven.
"If you want to do something. You remember. You do it with no regrets
If you want to fight, you put one foot in front of the other and you fight." Steven said seriously before walking forward sending his Metagross into battle.
She watched the battle. It was nearly 5 against 1.
'Walk in with no regrets.'
"Metagross!"
"Uh." Crystal looked up, And readied Braixons pokeball.
'If I do this....No. you walk in with no Regrets, No regrets, no' a loud explosion went off..
Dust was everywhere. Crystal could only see the outline of Steven and Metagross.
She breathed in,Breathed out.
'No regrets!' Crystal Took a hold of Braixons pokeball and ran forward.
"Alright Braixon. Use hidden power now!" Crystal called, large blue balls of energy were thrown at the pokèmon in captur of team Aqua..
"Braixon quick grab that vulpix!" Crystal yelled.
"Braixon!" Braixon yelped as she ran for the Snow white fox pokèmon.
"And just who do you think you are brat?! Running into battle with no hesitation. Do you have no respect for your life?!" A grunt yelled
"I'm not gonna weasily stand by and watch pokèmon get hurt when I know there is something I can do!" Crystal yelled.
"Oh yeah then do something about this. Toxic spikes go!" The grunt called.
Small stones full of poison where being shot at Crystal. She covered her arm waiting for the stones to stab her. Instead,
"Quick Stop them from hitting Crystal!"
Crystal looked up. She saw a Shiny mega latios, and a girl, she had Emerald green hair, a white dress with light green flower design. It had an over cover showing the shoulders with the same light green flower pattern.
Slowly the shiny mega latios floated to the ground and the girl jumped down
And so did Diantha,
"Crystal, Diantha, Steven." Said the girl.
"Take the vulpix to the pokèmon center ill clean up here" The voice was monotone.
"Right away!" Steven said.
"Diantha Crystal this way!"
"Right"

Crystal ran into the pokèmon center.
"Nurse joy help!" Steven said.
"Oh my. What happened?" Nurse joy asked taking the poisoned pokèmon.
"Team Aqua had poison her" Crystal said,
"Very well. I'll take care of her" Nurse joy said. She walked away.

~~~~~~~~~~~
"I'm happy to announce that the pokèmon will be just fine. Crystal stood up to see the vulpix but instead, the vulpix just ran for the door. And out of the pokemon center.
"Uh. Maybe it didn't want to be with a trainer" Crystal said.
"Listen its been a long hour. How about you two get back to your hotel. And then we'll see you in the morning" Steven said.
"Sounds good to me." Crystal said.
"Are you sure?" Diantha asked Steven nodded.
"Ok then. Let's go Crystal, say hi to Verdellian for me" Diantha said walking out of the pokemon center with Crystal.