This is a better Demystify, plain and simple. "But why?" I can hear people cry out from atop the highest mountains, "It does the exact same thing for the exact same price!" Sometimes children, it's not the present that matters, it's the box it comes in. The major difference in between Demystify and this card that elevates this card to a higher stature is the word Arcane. Back in the days of Kamigawa block, "Arcane" usually meant overcosted and underpowered (for example Cut the Earthly Bond or First Volley) but it gave a few benefits. Splice allowed you to combine your spells into one so that you only lost one card, but it could only be done with Arcane spells. There were also a lot of creatures and artifacts that worked with Arcane spells. Two of the scariest cards were Kyoki, Sanity's Eclipse and Oyobi, Who Split the Heavens. The only downfall to this card is the same downfall that Demystify has: it only targets enchantments. But, what else can you expect for 1 mana?
Pros: Instant speed enchantment destruction, cheap Arcane spell
Cons: Only targets enchantments