This is a useful trick in Super Smash Bros Brawl that a lot of people don't know about. Some of the better players would say that it's old news, but the majority of the smash universe has no clue what I was talking about before this. Btw, I discovered it last summer but kept it secret for a while.
Sorry to disapoint you, but this was known since Ness was introduced in the official blog.
Lucas' PSI Magnet does damage while Ness' pushes.
I personally find Ness a hardcore version of Lucas