MTL - Harry Potter’s Book of Sin - Chapter 27 Merlin's Secret

The peerless Demon Lord had been reborn. He used a dragon blade to sweep away powerful enemies from every direction and traversed the entire city, attracting countless beauties.

What would you do if you could control and use your Karma?

A continuation from where High School DxD Volume 25 left off.

“Before the towers fell, before everything was consumed by darkness...”Leo Astralis whispered to himself while traversing through the rubble of the ancient structure.His body bore the scars of survival, bite marks that throbbed against the coarse, blood-stiffened fabric of his clothing.“..I wonder what the world was like.”After humanity failed to complete the Tower almost 700 years ago in time, it exploded, spreading monsters all over the word.Even the system, which blessed humans with power, had abandoned them. Or did it?[Run]A singular message urged Leo to escape, yet it was short lived as was he was caught like an animal in a trap.And just like an animal he lashed out until the very end, taking one of the captors to the grave with him.But as darkness closed in, the system spoke again.[One time Regression activated][Congratulations. You've activated the Heart of the System]