Depends on what you want. This week I didn't play too many SOA decks so I used Copper. Other weeks I used Tessa Cr. It all depends on your play style though and how you like to use your cards.
Tessa Cr is good against both SoA and SoB, but Copper's spectacular 8 damage makes him worth the risk of SoA because he 2HKO's with a lot of very good choices.
Owen is also a good choice if your aim is to 2hko and can't afford Copper or Tessa Cr.