The Last Tomb Keeper

The MC is a really poor student that loves playing games One of his friends is a popular student detective that convinces him into helping with a murder case After viewing the last moments of an old man being held at gun point the scene forces the MC into a virtual reality game dropping him off at a desert landscape with some pyramids The MC goes with the flow and the first thing he sees is a BOSS sand monster and a quest option Like any MC he expects to defeat the Boss to win right No it turns out hes the last Gravekeeper and hes supposed to protect the treasure against the Tomb Raiders That old man He was his grandfather and they meet in virtual reality