note that the abilities 'paradox' and 'devour' have their limitation build in in the targeting.
I think that, rather than picking a random target and checking if it can be targeted,
it should be picking a random viable target.
same for if a part of the field is immaterial.
Also, I think that if there are no viable targets, it should not target the other field.
It means you cannot kill the last creature/destroy the last permanent.
I assume that if you were to destroy this with your pulverizer, it does not trigger.