The Unimplemented Overlords Have Joined the Party!, Vol. 1 — Nagawasabi64

THREE'S A CROWD… BUT SIX OVERLORDS?!Young gamer Shuutarou is among the lucky few chosen to playtest Eternity, the latest VRMMORPG, and he wastes no time in activating his unique Create Dungeon skill…at the exact moment the game glitches! Now he and his fellow playtesters are trapped, and their lives are at stake. Shuutarou happens to end up in the one area that has yet to be patched into the game: the final-boss lair where the six Evil Overlords lurk. They promptly declare him their master -- and with Eternity's strongest baddies on his team, Shuutarou is up for any adventures this new life throws at him!