True, she's a little expensive, at six mana, but for that you get an immediate boardwipe that benefits you far more than your opponents
This list will focus on cards with an exact red+white color identity
Nadu, in case you didnt realize, is pretty broken
I don't know if this card is any good outside of, like, Commander, but it's a cool design
If your opponent takes out Avacyn, they've got one turn at least to deal with the Shepherd before it brings her right back in a frightful bit of synergy
Search the Premises is a three generic, one white enchantment that works in a similar space to things like Ghostly Prison and Norn's Annex in attempting to dissuade enemy attackers