Rin wouldn't know about demonic beasts and their cores.
Demonic beast is powerful because they have superhuman abilities and they also come with their own magic spells.
With magic spells come the necessary cost to generate and store magic power.
Demonic beasts stored their energies in their demonic cores.
These cores grew as the demonic beasts grew.
These sources of energy made it possible for various medicines, items, and Armament to be made with their cores. It is also why high-level cores cost a fortune.
Rin is holding a tier 8 demonic beast core. The magic power within is more than a century's worth. Rin just couldn't accurately gauge it.
Any jewel mage would drool at the sight of a stone capable of holding centuries' worth of magic power.
She forgot that Wu Yan is her enemy. She grabbed him by his shoulders and got closer.
With her red lips and hot breath on his face, Wu Yan felt a bit out of the water.
He thought Rin was going to let him cop another feel.
He pushed her back into her seat.
"It's just a gemstone, calm down."
"Just a gemstone?"
"Do you know how much this thing costs?"
"Well, I do."
He scratched his cheeks.
"Just calm down, will you?"
She sighed after seeing Wu Yan's nonchalant look.
"You're obviously not a jewel mage so you don't know the true worth of a stone like this."
Wu Yan rolled his eyes.
"I know a lot of magic spells but jewel magic isn't one of them."
He knows Onmyojutsu, Alchemy, old magic, Barrier art, Kotodama, and other esoteric spells.
The 103,000 tomes of magic in his head contained so many spells Rin probably wouldn't fathom understanding a tenth of it.
He knows a little about jewel magic but not to the extent of a specialized expert like Rin.
Wu Yan admitted his ignorance in this field.
"Jewel magic is rare among magicians."
Rin puffed her chest out.
"Our Rin family has designed a system for this. Even the other jewel magicians of this world can't compete with us. Luvia only has the cash, not the technique, hahaha..."
Rin started tooting her own horn.
I mean, I am sure the other magicians have their own spins on this magic.
Wu Yan ignored her puffery.
"You can have the stone."
"What are you planning here?"
Wu Yan paused.
"Why are you giving your rival a precious stone like this?"
Rin raised the demonic core in her hand.
"You should know I can make this stone capable of killing you, given the chance."
"A kill shot?"
Wu Yan laughed.
"You sure about that?"
"You don't believe me?"
"A century's worth of magic power. Once I put a spell in this. It can unleash something on par with Medusa's Noble Phantasm, think you can survive that?"
Wu Yan didn't say anything.
At his peak, even 100 times yesterday's Noble Phantasm isn't anything to make a fuss about.
But, he is currently level 75.
The attack yesterday could kill him if he let his guard down.
It's just that...
It isn't possible to kill an immortal being like a True Ancestor of Wu Yan's caliber.
He can regenerate.
"Well, should you be happier?"
Wu Yan grinned.
"You now have something you can use against me. And, you got it from me for free, I'd say that's a big plus, no?"
Rin scrutinized him, looking for clues that he might be plotting something.
"Fine, I will accept it."
Rin stored the core away.
"Tonight, you're collecting cards too?"
"That's the plan."
Wu Yan sipped his tea.
"What? You want to tell me to back off again?"
"At this point, I know it would be impossible to make you give up..."
"But, we can come to an agreement."
Wu Yan leaned forward.
"What kind of deal?"
"A win-win for now."
Rin took out a map.
There are various red marks on the map.
"There are Class Cards in all these spots."
Rin looked into his eyes.
"If we bump heads like yesterday then it would slow the collection process. You have to guard against us and we have to do the same. Honestly, it is a massive pain in the butt."
"We are all after cards so we will have to duke it out in the end."
"So, why don't we steer clear of each other until then? Wait until we collect all the cards and then fight for ownership over all the cards?"
Wu Yan stayed silent.
True, accidents can happen if too many people are stuck on a tense battlefield.
Wu Yan isn't sure what Rin and the others can do. It would be troubling if they interfered like yesterday.
Waiting for the final duel is the best way around this.
Rin also has her own qualms.
They knew they wouldn't be able to win in a straightforward contest for the cards.
At least, with this plan, they can buy time, get their hands on more cards, and think of plans to stop Wu Yan.
This is Rin's actual plan.
Rin picked a spot.
"We are going here."
Wu Yan replied.
"Fine, we will go to another place."