mew* mew sw and mew d

[PokeMontoya]

When any of these mews copy an attack since it is usually thought that they rewrite mew x into an attack do they do it in all cases as for example Bannette's spiteful pain. Are you allowed to search your discard for mew's and do the extra damage?

 

[PokePop]

You only rewrite it when it is referring to the Pokemon doing the attack.
Think about it. The Banette doing the attack is not in the discard pile, it is Active.
So that is not a self reference. That is a reference to a different card named Banette.

So, in that case, it is not changed.
Mew would have to have a Banette in the discard pile to get the extra damage.