Legendary Planeswalker — Sivitri
+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.
In a Two-Headed Giant game, creatures can attack your teammate and planeswalkers your teammate controls without requiring a life payment.