Shinka Tokusei de Saikyou Necromancer

After clearing the game Peccata for the twelfth time, Kim Jinhwan finds himself inside its world as Adrias Cromwell, a weak and cowardly character who always ends up dead! With six months left until he gets killed along with his master for practicing forbidden magic, Adrias starts training and gathering corpses to better his necromancy, determined to survive. But will this long-time gamer's necromancy skills and pre-existing knowledge be enough to change the sequence of events?

(Source: Tapas)