Number One Dungeon Supplier - Chapter 1978: Extra: Void World

Cho Ryu Hyang was good at math from a young age. When he enrolled into the The Theoretical Maths and Martial Arts School, the teacher, Jo Gi Chun, recognized Cho Ryu Hyang’s talent immediately and took him in.

Rhett never expected becoming king until he slayed an ice dragon out of self defense and fulfils an ancient dragon slayers prophecy which makes them to crown him as their king.Transported to a gloomy and medieval like world, he is faced with leading the dragon slayers, the weakest of slayers among other slayers - demon slayers, gargoyle slayers, ghost slayers and shadow slayers.But ruling isn't so glamorous as he had anticipated and he is instead a warrior, with a system like ability which he must level up by slaying Dragons.And to his disadvantage, the world he is his controlled by SLAYERIOUS, an unknown and unseen entity. But that won't stop Rhett, he intends on dominating his world and even daring to slay the strongest dragon still alive, ruieen.And who knows, he might just defeat SLAYERIOUS if he tries harder.[WSA 2025 ENTRY]

I've transmigrated to the Honkai World and became the future Herrscher of Ice, Kiana's cousin, Durandal's cousin, Ana Schariac.Hmph, I must become a Valkyrie aboard the Hyperion at all costs to survive!Come join the Ana fan club!Wait! I'm just a fictional character, not your wife!Players, you guys are so peculiar!Ah well, let's embrace the chaos!*****

What would you say is the most valuable thing in this world?