Discuss and learn French: French vocabulary, French grammar, French culture etc.
very very small and very hard to explain.
au-delà is more used.
par-delà is more literary.
I would say that "au-delà" is just to indicate "on the other side" and "par-delà" is used for the same meaning but with an idea of obstacle.
i'll just use au-dela all the time. Tx