If Starlit Mantle leaves the battlefield before its enters-the-battlefield triggered ability resolves, the creature it last enchanted before it left gains hexproof until end of turn
Or in other words, you can expect to see support for things like dinosaurs, pirates, merfolk and artifacts, as well as a couple of individually spicy cards that are bound to make a splash even in older formats like Historic Brawl
I agree with @jonandek , that $3.8k for a PSA 8 No Rarity Zard given the overall graded population for the card (159 graded by PSA overall, 33 PSA 8s)
As card #232 in a set with 182 printed cards, it sits in the secret-rare numbering pulled less often than anything in the regular checklist
However, its not enough damage to command a position in any deck, and either way your opponent is going to take a prize next turn