Crossbreed Priscilla

Priscilla can't attack or block and has Hexproof
until you have 10 or less life.
Ethereal 3( if a creature would deal combat damage
to this creature prevent that damage unless it's controller pays {3})
As long as you have 11 or more life creatures can't attack you unless their controller pays {2} for each attacking creature
When Priscilla does combat damage to a creature, prevent that damage and put that many
-1/-1 counters on that creature instead