(Im basing this off of a story I read where Red join team rocket and killed his brother, bearly leaving Blue alive, he had killed all his friends, Yellow Green, even the prof. XD mew sent him back to learn a lesson. It was really good, im just adding things and tweaking =3)
Mew nodded. "Now, don't take word for it but...I think this is the only way.." Mew said sadly.

Blue started laughing and She started whistling sweetly.

Red smiled at Blue.

"Only one way to find out." Red said telepathically

Mew nodded. "Are you gonna stick to it?"

Milotic stopped and started whistling the same tune, the snowflakes started falling again.

"Yes." Red said

"Good.." Mew stated, before fading.
Articuno flew down and Blue pet it. "Hey...I missed you.." She whispered.

Red stayed silent

Blue looked at Red and smiled. "it's friendly, go ahead..."

Red petted the Articuno

It closed it's eyes and nuzzled into it's head.

Red smiled and continued petting it

It smiled and cooed. Blue snuck a pokeball into Red's other hand, it was small and already used. "It's yours." Blue stated with a smile. Articuno went into the pokeball that was in his hand.

"Wow..." Was all Red could say

Blue smiled. "I was just reading and it flew to me, I played with it and it found my bag, rumaged through it while I fed my Milotic and it caught itself." Blue stated.

"That's amazing." Red said

Blue smiled shyly. "It had hurt it's wing the other day when it had visited me last, it flew off and I didn't see it for a week, it looks fine now though, just keep an eye on it, loves to play whenever it can." Blue stated.