The Overpowered Support

Story:

Ho Kim, an avid enjoyer of the RPG "Dragon Slayer Academy", is the single most powerful support in the game. After spending countless hours, he eventually manages to reach the major milestone of raising 1,000 heroes to S-rank and is presented with a hidden quest. Tempted by the possibility of raising his S-rank heroes to the more powerful EX-rank, he accepts the quest without a second thought, only to find himself trapped inside the game world...