The Doomsday Cultivator

In a world overrun with deathwalkers, the factotum disciple, Chen Yuan, accidentally awakens a Universal Extraction System after getting attacked by some lowlifes. The System can extract cultivation, cultivation methods, spirit energy and so on from all non-living things. With the aid of the System, Chen Yuan begins to level up by killing monsters. But unbeknownst to him, hidden behind his ordeals is a giant conspiracy targeted at him...(Source: WebComics)