Once during your turn (before your attack), you may put Pikachu from your hand onto Pichu (this counts as evolving Pichu) and remove all damage counters from Pichu.

Energy Retrieval

Search your discard pile for up to 2 basic Energy cards and attach them to 1 of your Pokémon. Put 1 damage counter on that Pokémon for each Energy card attached in this way.