Sivitri, Dragon Master (Foil Etched)

[+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.
Sivitri, Dragon Master can be your commander.