Odd keystone

"Cynthi, are you sure you want to go out? It's raining pretty hard."
"It's the perfect time to go out! The rain washes away the dirt and uncovers all sorts of things!"
Orchid sighed. "Alright, but I'm staying inside. Be safe out there - I love you."

--

It had taken some time for Orchid to get used to Cynthia's rainy-day treks - at first, she was a bit concerned for Cynthia's wellbeing, but she eventually just accepted it as one of her quirks. While Orchid was more content to stay inside and research from there, Cynthia was thirsty for the thrill of digging up something new.

So, there Cynthia was - gallantly riding her garchomp as it quickly waded through the buildup on mud, using its sense of smell to trace it's way back to Cynthia's dig site. She'd been working on the site for weeks now, after Orchid's research revealed it to be a likely hotspot for archeological activity. Supposedly, it was one of the initial living situations set up by the ancient Draconids who first traveled to Sinnoh. So, with Emerald's permission, of course, Cynthia was off to find out what she could discover about the history of her region.
When garchomp arrived at the site, Cynthia gracelessly jumped off of it's back and into the mud in a splatter. Re-adjusting her upper coat, she got to work examining the cliff wall she had been frequenting. It didn't take long for her to find something that jumped at her, though. Jutting out of the cliff, uncovered by rain, was a strange-looking rock. It wasn't just any rock, though; the runes on the side indicated it must've been an object fantastically rare - an odd keystone, so they were called. They had quite a reputation for being cursed and bad to be around, but Cynthia had been wanting to examine one for so long. She couldn't help it, and carefully excavated the stone out of the muddy soil it was stuck in. Garchomp seemed to be skittish around the stone, so Cynthia was forced to walk back home through the mud as her pokemon cautiously followed behind.

When Cynthia got home, Orchid had been working in the kitchen, as to meet her by the door. She slammed the door open loudly, and when Orchid jolted up from the sound and turned to look, she saw Cynthia sopping wet and covered in mud, carrying something in her equally drenched bag. In the silence, Cynthia's garchomp quiet slipped past, shook the water off, and wandered upstairs to take a nap and to get as far away from the keystone as possible. 

"You look like a mess." Orchid noted, turning her attention back to her work as Cynthia slowly removed her heavy layers.
"I feel like a mess." Cynthia replied. "Garchomp wouldn't let me ride her on the way back so I had to walk - I probably need to towel off"
Cynthia finished taking off her coats, only to find that they had soaked through onto her clothes. She let out a frustrated groan, as she set the bag containing the keystone on the counter next to her wife and trudged upstairs to change clothes.

Cynthia changed into a dry pantsuit, and was about to put her hair up in a ponytail before she was called down by Orchid, who shouted up the stairs in a concerned tone.
"Cynthi, can you come down?"
Cynthia finished tying her hair and headed downstairs, to see Orchid standing her the bag containing the keystone.
"Is that what you found out there?" she asked, pointing to the bag.
"Oh yeah, let me show you!"
Cynthia excitedly opened the button on the bag and pulled the keystone out. Orchid scanned the rock for a few seconds before suddenly realizing what it was. Upon realization, Orchid sucked in air and raised her shoulders up in shock.
"CYNTHIA, WHAT THE HELL IS THIS DOING IN OUR HOUSE?!"
Cynthia's expression quickly turned from a smile to concern upon seeing orchid's reaction.

"It's a keysto-" Cynthia was interrupted by Orchid.
"I KNOW what it is, what I'm wondering is; why on earth you'd take this with you!"
Cynthia thought for a bit. Why did she take it with her, anyway? She wanted to study it, but she doubted Orchid would like that answer.
Cynthia's thought was cut off by Orchid again. "Look, just... that thing's bad, ok? You do know about tales of these being heavily hexed, right?! They're used to channel souls of the dead into the mortal realm!"
"Well, I think life for us is weird enough, what more is a haunted rock?"
Orchid looked at Cynthia blankly, before stifling some laughter. "Somehow, you always seem to make things sound appealing - I love that about you, you know? Even if this thing is curs-"

Orchid's speaking was cut off once she had noticed the black mist emanating from the keystone. Cynthia soon noticed as well, and the two backed off from it, holding each other. An otherworldly cry came from the rock, and a purple ectoplasm slowly stemmed out of the rock to form an amorphous blob circled by green orbs. It seemed to grow what looked like a face, and let out another cry, lunging towards Cynthia and Orchid. Cynthia quickly tried to cover for Orchid, anticipating a blow, but that blow never came. She looked up, to see that the spirit couldn't lunge far enough towards the two - it was bound to its stone.
The spirit seemed upset, and Orchid realized this. Orchid had made a promise to herself to try and not get involved in the supernatural, but it appeared she had little choice.
"He... hello? We aren't here to hurt you, this is all just a simple misunderstanding..."
The spirit cocked it's face to the side, like it could acknowledge Orchid was speaking, but not understand what she was saying. The two sat for a bit before Cynthia got an idea - she repeated what Orchid had said to the spirit, but in Draconid. As soon as she did, it's expression changed to what could resemble a slight smile, before it nodded. Cynthia and Orchid both had relief wash over their faces, realizing that whatever it was, it didn't seem innately harmful once spoken to. 

The two exchanged words with the spirit in Draconid for a while, and realized it didn't seem to quite understand more advanced phrases and words. It was then Orchid had an epiphany;
"Cynthia! I think I know what this thing is!"
"What is it?" she replied, curious.
"It looks like illustrations I've seen of a spirit class pokemon known as spiritomb - an amalgamation of spirits." Orchid paused. "From how it understands what we're saying, it must be the spirits of different pokemon that've been channeled into the keystone! They must recognize Draconid from their trainers all those years ago."
Cynthia nodded, because having a realization herself and gaining a smug grin.
"Does that mean I can catch it?"
"What- I-... I mean... maybe? It seems friendly, but I'm not sure how I feel about having this type of pokemon in the house..."
"C'mon Orchid, it likes you too!"
Orchid sighed. "Fine, I guess if you keep it in it's pokeball most of the time, it wouldn't hurt."

Cynthia grinned and reached for an ultra ball that she kept in her bag. The spiritomb seemed curious about the ball, and was about to make a reaction as Cynthia threw it.
1... 2... 3... click! Spiritomb was caught! Cynthia looked at the ball with a smile, and while Orchid's smile was warier, she could still appreciate Cynthia finding a strange new team member.

--

That night, the two exchanged conversations as they were falling asleep.

"Cynthi... when I'm gone, do you think I could be channeled into a keystone so I could visit?"
"Huh? What do you mean?"
"I dunno... I'm just... thinking. Those pokemon are there long after their trainers have gone, long after they were supposed to live... I wonder if I could do the same."
Cynthia paused
"I'm not sure how good you'd look in purple, Orchid"
Orchid snickered. "Well, if it'd mean seeing you again after I'm gone, so be it."
"There's still a long time until then, like 20-something years! We still have a lot of time together until then."
"Right... well, no matter what, I'll love you Cynthia, even if you put my soul into a rock."
"Hah... I love you too, Orchid."