Demon King & Hero - Special: Q&A 2

The whole world is subjected to a highly dangerous standardised exam called the Global University Entrance Examination. Answering questions by putting their lives at stake, they would live if they passed the test. Every month the exam will undergo reformation while, occasionally, it is random.

- Description from Novelupdates

Betrayed and left for dead, Richard Blackwood—formerly known as the world renowned hero Astralis—awakens a decade later to find the world has moved on, and an imposter now wears his mantle. Disguised as a rookie in the Mage Guild, he quietly hunts for answers.'If my little sister is levelled above me, then what about everyone else? How much stronger have the bastards who betrayed me grown while I was dead?'Richard must grow stronger once again, and rise much higher than the S-Rank.'What the fuck? I almost die, and I get a power up?'Not harem.

Lyra Shedd faced a brutal betrayal—her grandfather violently stole her superpower and handed it to her nemesis; her beloved younger brother, in his stupidity, leaked their only hidden assets to her enemies.Once a genius, she was reduced to nothing, drifting in the sea of stars.During her most agonizing years, she finally accepted the fact that her family didn't love her. Realizing she had nothing left to lose, she decided to throw off all moral restraints and become a villain!On her journey of revenge, she encountered many handsome men—but to a cold-blooded villain, they were nothing but tools for her vengeance!This time, she would make all those who pushed her to the brink tremble and scream for mercy!

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