Wiktionary
vb. (context idiomatic English) To damage; to treat harshly; to produce ill effects on.
Usage examples of "do a number on".
If we do have to do a number on someone, it's usually to make an example of them and we do something flashy like burn down their house or break their legs.
The talk on the street is that someone's hired the Ax to do a number on Skeeve.
Longbowmen will do a number on them, though, at least at any range under a hundred meters.
It would do a number on a chunk of Manhattan, but most of the rest of the city would just suffer fallout.
The Japanese kid, and maybe an entire slew of ghosts, formed up to do a number on Burnside.
You woke up in a room and this alien ghost tells you the human species is extinct and asks you to do a number on me.
The problem is that the wake from the first Tseetsk salvo will still do a number on our systems.
With Ortius, one could never be certain when the chubby little sailing master was going to do a number on you.