Polukranos, Unchained [Theros Beyond Death]

Polukranos enters the battlefield with six +1/+1 counters on it. It escapes with twelve +1/+1 counters on it instead.
If damage would be dealt to Polukranos while it has a +1/+1 counter on it, prevent that damage and remove that many +1/+1 counters from it.
1BG: Polukranos fights another target creature.
Escape—4BG, Exile six other cards from your graveyard.