At the low cost of one generic, one blue, you could very quickly build an army of Persistent Petitioners
This was an experiment that works and I feel makes it some level of success
If people start moving in on more Ravenous Chupacabras, Dive Downs stock will rise, but stick with Spell Pierce for now
While mana intensive, the ability to repeatedly refute an opponent's turn by bouncing their guy combined with the ability to use Disappear as a way to "protect" your creatures in combat (cast Disappear on it and then attack freely, knowing you can save it from lethal damage) made for a very potent enchantment that acted more as a sorcery than an enchantment
You also wouldnt play Llanowar Dead over Three Visits as Three Visits only requires green mana, it can fetch lands that tap for multiple colors, and its ramp effect isnt tied to a creature that will likely disappear after your games first board wipe