Arnu, the Untarnished

Defender
When a creature enters the battlefield on your
side of the field, place a Purity counter on Arnu,
the Untarnished.
Arnu, the Untarnished and creatures you control
have Ward {x}, where X is the number of Purity counters on Arnu, the Untarnished.
If Arnu, the Untarnished has 8 Purity counters,
or is targeted with a spell or ability, transform
Arnu, the Untarnished.