Treant

"That's it?" Mathias asked in dumbfounding.

"Yep, that's it."

Nial merely smiled as he stored the corpses of the Blackbone Bears in his spatial ring.

One of the four Blackbone Bears had turned into an Origin crystal. 

It was as large as the fist of an infant and radiated a whitish-blue light. 

"Lowest quality Superior grade, not bad." 

The Lowest quality Superior grade Origin crystals were perfectly suited for both Mathias and Nial. Using Origin crystals of higher quality wouldn't increase their efficiency while Common graded Origin crystals didn't hold enough pure mana.

'Looks like Low Expert Dungeons are perfect for us, right now.' Nial thought with a smile.

The Blackbone Bear corpses were quite useful for them. Not only were their bones used to create weapons, potions and specific inscription solutions but some abilities required making use of the bear's black bones as well.

That's why they would fetch a good price.