Eternatus, Restored

When Eternatus, Restored enters the battlefield,
remove all +1/+1 counters from creatures, then put twice as much on this creature. Other creatures
can't have +1/+1 counters put on them.
You may cast instants and sorceries without paying their mana cost.
If Eternatus isn't targeted by at least one instant or sorcery on your turn, remove all +1/+1 counters
from it and transform it.