The Immortal Necromancer

When a game-like system merges with reality, the world's rules are rewritten, and humanity enters an age where everyone can change their class. Genius Aiden Eastwood awakens as a Necromancer, a Hidden Class ridiculed for consuming its user's lifespan. But with his secret talent, the Undying Body, he summons golden undead legions, colossal Bone Dragons, and even unleashes the demon king Satan, leaving the world in awe.