This is just a rumor at the moment, but we could be having a weird fusions of split cards and flashback. It certainly has a feeling of being fake, probably because of the weird vertical and horizontal aspects of it, but nothing seem too off about it.
Dusk
Sorcery
Destroy all creatures with power greater or equal to 3
Dawn
Sorcery
Cast this sorcery only from your graveyard, then exile it.
Return all creature cards with power less than or equal to 2 from your graveyard to your hand.