Debuff Master

Han Taesung, a gamer for a living, is cornered at the edge of a cliff. "I have been watching you for a long time." Deus, a hidden NPC of level 999, appears In front of Taesung! "Would you like to become the disciple of the hidden NPC Deus?" "Yes!" Thus the master's teachings began!! "Two blows are not cool, you must defeat enemies in one blow." Taesung becomes a Debuff Master who knocks down enemies in single blow. Everyone will fall prey! Defeat them in one hit! (Source: Kakao Entertainment, translated)