I think it's valid to omit the conjunction in a parallel clause for effect, e.g.:
There can be no absolution, no forgiveness.
But is this still a valid variant of parallelism, or does the later phrase now serve as an aside that requires an extra comma? That is, should it be
There can be no absolution, no forgiveness for what he's done.
There can be no absolution, no forgiveness, for what he's done.
Somehow both look off to me. The conjunction-free parallel fragment is grammatical and common enough, e.g. "no harm, no foul", but can its use in a sentence be grammatical without re-adding a conjunction?