Sarlena of the Northern Verge

Flash, Valiant 2(Whenever a creature with power greater than this creature enters the battlefield, you
may have this creature fight that creature. If you do, this creature gets +2/+2 until end of turn.)
As long as it is your turn, prevent all damage that would be dealt to Sarlena.
Whenever Sarlena attacks, you may exile target black or red permanent.