Cynthia, Sinnoh Champion

+1: Until your next turn, creatures can’t attack you or planeswalkers you control unless their controller pays 2 life for each of those creatures.
-3: Search your library for a Dragon card, reveal it, put it into your hand, then shuffle.
-7: Destroy all non-Dragon creatures. Cynthia can be your commander. Cynthia is a proxy of Sivitri, Dragon Master.