Lucario can use Band, Specs and Scarf all reasonably well.
He has the stats and movepool for any of these roles, the typing still rocks and the fact that Luke has so many different sets that people actually use gives him the same surprise factor that Salamence had.
Basically when you see a Lucario you typically think its a boosting set, they used to be mostly SD so NP became popular to lure and kill the physical walls Lucario used to attract.
Now that NP is popular too when an opponent sees a Lucario they don't know whether its SD/NP/Band/Specs/Scarf and as such it makes Luke hard very to counter.
He has the stats and movepool for any of these roles, the typing still rocks and the fact that Luke has so many different sets that people actually use gives him the same surprise factor that Salamence had.
Basically when you see a Lucario you typically think its a boosting set, they used to be mostly SD so NP became popular to lure and kill the physical walls Lucario used to attract.
Now that NP is popular too when an opponent sees a Lucario they don't know whether its SD/NP/Band/Specs/Scarf and as such it makes Luke hard very to counter.