Dungeon Defense (LN)

Become the hero and defeat the 72 Demon Lords. The game that was boasted as the absolute hardest strategy game, 『Dungeon Attack』. I used to be the ‘hero’ that had accomplished everything in this game, but after answering a suspicious survey, I found myself in the game as the weakest Demon Lord, [Dantalian]. With only my eloquent tongue and my memories of conquest as a hero~. In order to survive as Dantalian. I shall tear this world apart. — Description from novelcodex.org