I Became a Mythical Knight King

Fantasy Monarch undisputed #1 ranked player is Black Knight 09 Cheon Yoo Seong. What came to him was a new offer, ‘Successor of the Holy King’? [Would you like to inherit the power of Holy King Arthur Pendragon?] “Yes, I will.” [Once you choose, there is no turning back.] “I said I will.” [This is the final confirmation.] “…….” At this point, it feels a bit cheap. In the Age of the Ominous Stars where humanity is heading towards extinction, I become the knight king who will save humanity.