The Lord Who Levels Up by Devouring

A brief description of the manhwa The Lord Who Levels Up by Devouring:

After the continent is destroyed and humanity’s last hope is defeated, Adrian absorbs the heart of his dying friend, the Hero Ian, using his unique ability [Devour] and travels back 15 years into the past. Armed with his past-life combat experience, a mysterious Player System, and the ability to endlessly grow stronger by devouring others’ powers, Adrian begins his journey to hunt down those responsible and consume their hearts. Show more