How strong is this?

[Bernkastelll]

the quote from the novel: "Simply put, a large monster that can turn three or four apartment buildings into a field of ashes will not have a scratch even if it is showered with grenades like rain."

how strong is that

 

[Vzearr]

Not quantifiable in the sense that we don't know how long or how many hits it would take for "a large monster" to do that. It calls for "At least Building level" though.